diff --git a/hdu853/01.cpp b/hdu853/01.cpp
new file mode 100644
index 0000000..3ee04af
--- /dev/null
+++ b/hdu853/01.cpp
@@ -0,0 +1,15 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+typedef long long ll, i64;
+int main()
+{
+    return 0;
+}
\ No newline at end of file
diff --git a/hdu853/02.cpp b/hdu853/02.cpp
new file mode 100644
index 0000000..3ee04af
--- /dev/null
+++ b/hdu853/02.cpp
@@ -0,0 +1,15 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+typedef long long ll, i64;
+int main()
+{
+    return 0;
+}
\ No newline at end of file
diff --git a/hdu853/03.cpp b/hdu853/03.cpp
new file mode 100644
index 0000000..3ee04af
--- /dev/null
+++ b/hdu853/03.cpp
@@ -0,0 +1,15 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+typedef long long ll, i64;
+int main()
+{
+    return 0;
+}
\ No newline at end of file
diff --git a/hdu853/04.cpp b/hdu853/04.cpp
new file mode 100644
index 0000000..3973d0d
--- /dev/null
+++ b/hdu853/04.cpp
@@ -0,0 +1,50 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+typedef long long ll, i64;
+ll gcd(ll a, ll b) { return b == 0 ? a : gcd(b, a % b); }
+struct prob
+{
+    int a, b;
+    OPL(prob, rhs) { return a < rhs.a || (a == rhs.a && b > rhs.b); }
+};
+int main()
+{
+    int T, n;
+    scanf("%d", &T);
+    while (T--)
+    {
+        priority_queue<prob> H;
+        ll hi = 0, lo = 1, g, asum = 0;
+        scanf("%d", &n);
+        for (int i = 0; i < n; i++)
+        {
+            prob p;
+            scanf("%d%d", &p.a, &p.b);
+            if (p.a > p.b) swap(p.a, p.b);
+            H.push(p);
+            asum += p.a;
+            if (i & 1 ^ 1)
+            {
+                p = H.top();
+                hi = (asum - p.a) * (p.a + p.b) + p.a * p.b;
+                lo = p.a + p.b;
+            }
+            else
+            {
+                hi = asum, lo = 1;
+            }
+            g = gcd(hi, lo);
+            hi /= g, lo /= g;
+            printf("%lld/%lld\n", hi, lo);
+        }
+    }
+    return 0;
+}
\ No newline at end of file
diff --git a/hdu853/05.cpp b/hdu853/05.cpp
new file mode 100644
index 0000000..3ee04af
--- /dev/null
+++ b/hdu853/05.cpp
@@ -0,0 +1,15 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+typedef long long ll, i64;
+int main()
+{
+    return 0;
+}
\ No newline at end of file
diff --git a/hdu853/06.cpp b/hdu853/06.cpp
new file mode 100644
index 0000000..3ee04af
--- /dev/null
+++ b/hdu853/06.cpp
@@ -0,0 +1,15 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+typedef long long ll, i64;
+int main()
+{
+    return 0;
+}
\ No newline at end of file
diff --git a/hdu853/07.cpp b/hdu853/07.cpp
new file mode 100644
index 0000000..3ee04af
--- /dev/null
+++ b/hdu853/07.cpp
@@ -0,0 +1,15 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+typedef long long ll, i64;
+int main()
+{
+    return 0;
+}
\ No newline at end of file
diff --git a/hdu853/08.cpp b/hdu853/08.cpp
new file mode 100644
index 0000000..77802af
--- /dev/null
+++ b/hdu853/08.cpp
@@ -0,0 +1,39 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+typedef long long ll, i64;
+ll gcd(ll a, ll b) { return b == 0 ? a : gcd(b, a % b); }
+ll f(ll n, ll m)
+{
+    ll x = n;
+    do
+        if (gcd(++x, n) == 1) m--;
+    while (m);
+    return x;
+}
+int main()
+{
+    ll T, k, m;
+    scanf("%lld", &T);
+    while (T--)
+    {
+        scanf("%lld%lld", &k, &m);
+        bool flag = true;
+        for (ll n = 1; n < 10000; n++)
+            if (((f(n, m) - n) ^ n) == k)
+            {
+                printf("%lld\n", n);
+                flag = false;
+                break;
+            }
+        if (flag) puts("-1");
+    }
+    return 0;
+}
\ No newline at end of file
diff --git a/hdu853/09.cpp b/hdu853/09.cpp
new file mode 100644
index 0000000..3ee04af
--- /dev/null
+++ b/hdu853/09.cpp
@@ -0,0 +1,15 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+typedef long long ll, i64;
+int main()
+{
+    return 0;
+}
\ No newline at end of file
diff --git a/hdu853/10.cpp b/hdu853/10.cpp
new file mode 100644
index 0000000..3ee04af
--- /dev/null
+++ b/hdu853/10.cpp
@@ -0,0 +1,15 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+typedef long long ll, i64;
+int main()
+{
+    return 0;
+}
\ No newline at end of file
diff --git a/hdu853/11.cpp b/hdu853/11.cpp
new file mode 100644
index 0000000..3ee04af
--- /dev/null
+++ b/hdu853/11.cpp
@@ -0,0 +1,15 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+typedef long long ll, i64;
+int main()
+{
+    return 0;
+}
\ No newline at end of file
diff --git a/hdu853/12.cpp b/hdu853/12.cpp
new file mode 100644
index 0000000..31890b4
--- /dev/null
+++ b/hdu853/12.cpp
@@ -0,0 +1,28 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+typedef long long ll, i64;
+const int N = 1e5 + 50;
+int a[N];
+int main()
+{
+    int T, n;
+    scanf("%d", &T);
+    while (T--)
+    {
+        scanf("%d", &n);
+        for (int i = 0; i < n; i++) scanf("%d", a + i);
+        sort(a, a + n, greater<int>());
+        ll cnt[] = {0, 0};
+        for (int i = 0; i < n; i++) cnt[i & 1] += a[i];
+        printf("%lld %lld\n", cnt[0], cnt[1]);
+    }
+    return 0;
+}
\ No newline at end of file
diff --git a/hdu853/CMakeLists.txt b/hdu853/CMakeLists.txt
new file mode 100644
index 0000000..ff9cee8
--- /dev/null
+++ b/hdu853/CMakeLists.txt
@@ -0,0 +1,18 @@
+cmake_minimum_required(VERSION 3.0)
+set(CMAKE_CXX_STANDARD 17)
+if(MSVC)
+    add_compile_options("/Zc:__cplusplus")
+endif()
+include_directories("D:\\PortableApps\\MSYS2\\mingw64\\include\\c++\\9.1.0\\x86_64-w64-mingw32")
+add_executable(01 01.cpp)
+add_executable(02 02.cpp)
+add_executable(03 03.cpp)
+add_executable(04 04.cpp)
+add_executable(05 05.cpp)
+add_executable(06 06.cpp)
+add_executable(07 07.cpp)
+add_executable(08 08.cpp)
+add_executable(09 09.cpp)
+add_executable(10 10.cpp)
+add_executable(11 11.cpp)
+add_executable(12 12.cpp)
diff --git a/nowcoder887/A.cpp b/nowcoder887/A.cpp
new file mode 100644
index 0000000..3ee04af
--- /dev/null
+++ b/nowcoder887/A.cpp
@@ -0,0 +1,15 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+typedef long long ll, i64;
+int main()
+{
+    return 0;
+}
\ No newline at end of file
diff --git a/nowcoder887/B.cpp b/nowcoder887/B.cpp
new file mode 100644
index 0000000..3ee04af
--- /dev/null
+++ b/nowcoder887/B.cpp
@@ -0,0 +1,15 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+typedef long long ll, i64;
+int main()
+{
+    return 0;
+}
\ No newline at end of file
diff --git a/nowcoder887/C.cpp b/nowcoder887/C.cpp
new file mode 100644
index 0000000..3ee04af
--- /dev/null
+++ b/nowcoder887/C.cpp
@@ -0,0 +1,15 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+typedef long long ll, i64;
+int main()
+{
+    return 0;
+}
\ No newline at end of file
diff --git a/nowcoder887/CMakeLists.txt b/nowcoder887/CMakeLists.txt
new file mode 100644
index 0000000..766e4de
--- /dev/null
+++ b/nowcoder887/CMakeLists.txt
@@ -0,0 +1,17 @@
+cmake_minimum_required(VERSION 3.0)
+set(CMAKE_CXX_STANDARD 17)
+if(MSVC)
+    add_compile_options("/Zc:__cplusplus")
+endif()
+include_directories("D:\\PortableApps\\MSYS2\\mingw64\\include\\c++\\9.1.0\\x86_64-w64-mingw32")
+add_executable(A A.cpp)
+add_executable(B B.cpp)
+add_executable(C C.cpp)
+add_executable(D D.cpp)
+add_executable(E E.cpp)
+add_executable(F F.cpp)
+add_executable(G G.cpp)
+add_executable(H H.cpp)
+add_executable(I I.cpp)
+add_executable(J J.cpp)
+add_executable(K K.cpp)
diff --git a/nowcoder887/D.cpp b/nowcoder887/D.cpp
new file mode 100644
index 0000000..3ee04af
--- /dev/null
+++ b/nowcoder887/D.cpp
@@ -0,0 +1,15 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+typedef long long ll, i64;
+int main()
+{
+    return 0;
+}
\ No newline at end of file
diff --git a/nowcoder887/E b/nowcoder887/E
new file mode 100644
index 0000000..a5e15b4
Binary files /dev/null and b/nowcoder887/E differ
diff --git a/nowcoder887/E.cpp b/nowcoder887/E.cpp
new file mode 100644
index 0000000..c62b38f
--- /dev/null
+++ b/nowcoder887/E.cpp
@@ -0,0 +1,93 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+#ifndef _DEBUG
+#define _DEBUG 0
+#endif // !_DEBUG
+#define IFD if (_DEBUG)
+typedef long long ll, i64;
+const int N = 4e5 + 50;
+int X[N], Y[N], mp[N << 1];
+template <size_t sz>
+struct SegTree
+{
+#define L(x) ((x) << 1)
+#define R(x) ((x) << 1 | 1)
+#define avg(x, y) (((x) + (y)) >> 1)
+    struct Node
+    {
+        ll a, x;
+    } N[sz << 2];
+    void addtag(int k, int l, int r, ll v)
+    {
+        N[k].a += v;
+        N[k].x += (r - l) * v;
+    }
+    void pushdown(int k, int l, int r)
+    {
+        if (N[k].a == 0) return;
+        int m = avg(l, r);
+        addtag(L(k), l, m, N[k].a);
+        addtag(R(k), m, r, N[k].a);
+        N[k].a = 0;
+    }
+    void modify(int k, int l, int r, int x, int y, ll v)
+    {
+        if (x <= l && r <= y) return addtag(k, l, r, v);
+        int m = avg(l, r);
+        pushdown(k, l, r);
+        if (x < m) modify(L(k), l, m, x, y, v);
+        if (y > m) modify(R(k), m, r, x, y, v);
+        N[k].x = N[L(k)].x + N[R(k)].x;
+    }
+    int kth(int k, int l, int r, int sz)
+    {
+        if (l == r - 1)
+        {
+            return l;
+        }
+        pushdown(k, l, r);
+        int d = N[L(k)].x, m = avg(l, r);
+        return d >= k ? kth(L(k), l, m, k) : kth(R(k), m, r, k - d);
+    }
+};
+SegTree<N> st;
+int main()
+{
+    int n;
+    scanf("%d", &n);
+    {
+        ll a, b, c, m;
+        scanf("%d%d%lld%lld%lld%lld", X, X + 1, &a, &b, &c, &m);
+        for (int i = 2; i < n; i++) X[i] = (a * X[i - 1] + b * X[i - 2] + c) % m;
+        scanf("%d%d%lld%lld%lld%lld", Y, Y + 1, &a, &b, &c, &m);
+        for (int i = 2; i < n; i++) Y[i] = (a * Y[i - 1] + b * Y[i - 2] + c) % m;
+        for (int i = 0; i < n; i++)
+        {
+            if (X[i] > Y[i]) swap(X[i], Y[i]);
+            X[i]++, Y[i]++;
+        }
+    }
+    memcpy(mp, X, n << 2);
+    memcpy(mp + n, Y, n << 2);
+    sort(mp, mp + n + n);
+    int mpl = unique(mp, mp + n + n) - mp;
+    for (int i = 0; i < n; i++) X[i] = lower_bound(mp, mp + mpl, X[i]) - mp;
+    for (int i = 0; i < n; i++) Y[i] = lower_bound(mp, mp + mpl, Y[i]) - mp;
+    IFD
+    {
+        for (int i = 0; i < n; i++) printf("%d%c", mp[X[i]], " \n"[i == n - 1]);
+        for (int i = 0; i < n; i++) printf("%d%c", mp[Y[i]], " \n"[i == n - 1]);
+    }
+    for (int i = 0; i < n; i++)
+    {
+    }
+    return 0;
+}
\ No newline at end of file
diff --git a/nowcoder887/F.cpp b/nowcoder887/F.cpp
new file mode 100644
index 0000000..3ee04af
--- /dev/null
+++ b/nowcoder887/F.cpp
@@ -0,0 +1,15 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+typedef long long ll, i64;
+int main()
+{
+    return 0;
+}
\ No newline at end of file
diff --git a/nowcoder887/G.cpp b/nowcoder887/G.cpp
new file mode 100644
index 0000000..3ee04af
--- /dev/null
+++ b/nowcoder887/G.cpp
@@ -0,0 +1,15 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+typedef long long ll, i64;
+int main()
+{
+    return 0;
+}
\ No newline at end of file
diff --git a/nowcoder887/H.cpp b/nowcoder887/H.cpp
new file mode 100644
index 0000000..8e55521
--- /dev/null
+++ b/nowcoder887/H.cpp
@@ -0,0 +1,32 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+typedef long long ll, i64;
+bitset<32> BM;
+int main()
+{
+    int a, b, c;
+    while (~scanf("%d%d%d", &a, &b, &c))
+    {
+        long long cnt[] = {0, 0, 0};
+        for (int x = 1; x <= a; x++)
+            for (int y = 1; y <= b; y++)
+            {
+                if ((x & y) > c) cnt[0]++;
+                if ((x ^ y) < c) cnt[1]++;
+                if ((x & y) > c && (x ^ y) < c) cnt[2]++;
+            }
+        cout << (BM = a) << endl;
+        cout << (BM = b) << endl;
+        cout << (BM = c) << endl;
+        printf("%lld : %lld + %lld - %lld\n", cnt[0] + cnt[1] - cnt[2], cnt[0], cnt[1], cnt[2]);
+    }
+    return 0;
+}
\ No newline at end of file
diff --git a/nowcoder887/I.cpp b/nowcoder887/I.cpp
new file mode 100644
index 0000000..3ee04af
--- /dev/null
+++ b/nowcoder887/I.cpp
@@ -0,0 +1,15 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+typedef long long ll, i64;
+int main()
+{
+    return 0;
+}
\ No newline at end of file
diff --git a/nowcoder887/J.cpp b/nowcoder887/J.cpp
new file mode 100644
index 0000000..50ff33a
--- /dev/null
+++ b/nowcoder887/J.cpp
@@ -0,0 +1,37 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+typedef long long ll, i64;
+const int N = 1e5 + 50;
+ll a[N], b[N], c[N];
+int main()
+{
+    int n, k;
+    scanf("%d%d", &n, &k);
+    for (int i = 0; i < n; i++) scanf("%lld%lld", a + i, b + i);
+    for (int i = 1; i < n; i++) c[i] = b[i - 1] * a[i];
+    ll baseV = accumulate(c, c + n, 0ll);
+    ll mn = 0, mx = 0, mnt = 0, mxt = 0;
+    for (int i = 1; i < n; i++)
+    {
+    }
+    mn = min(mn, mnt), mx = max(mx, mxt);
+    if (k == 0)
+        printf("%lld", baseV);
+    else
+    {
+        ll cur = baseV;
+        ll minId = n;
+		for (int i = n; i; i--) {
+		}
+        printf("%lld", cur);
+    }
+    return 0;
+}
\ No newline at end of file
diff --git a/nowcoder887/K.cpp b/nowcoder887/K.cpp
new file mode 100644
index 0000000..b28f58d
--- /dev/null
+++ b/nowcoder887/K.cpp
@@ -0,0 +1,45 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+typedef long long ll, i64;
+const int N = 1e6 + 50;
+bool vis[N];
+int a[N];
+void read(int &x)
+{
+    int ch = x = 0;
+    while (!isdigit(ch)) ch = getchar();
+    for (; isdigit(ch); ch = getchar()) x = x * 10 + ch - '0';
+}
+int main()
+{
+    int n, m, q;
+    read(n), read(m), read(q);
+    for (int i = 1; i <= n; i++) read(a[i]);
+    for (int i = 1, x, y; i < m; i++)
+    {
+        read(x), read(y);
+        if (x == y) continue;
+        vis[x] = true;
+    }
+    for (int i = 1; i <= n; i++)
+    {
+        if (vis[i]) a[i] = 0;
+        a[i] += a[i - 1];
+    }
+    ll ans = 0;
+    for (int i = 1, x, y; i <= q; i++)
+    {
+        read(x), read(y);
+        ans ^= i * (a[y] - a[x - 1]);
+    }
+    printf("%lld", ans);
+    return 0;
+}
\ No newline at end of file
diff --git a/nowcoder888/A.cpp b/nowcoder888/A.cpp
new file mode 100644
index 0000000..21a092b
--- /dev/null
+++ b/nowcoder888/A.cpp
@@ -0,0 +1,19 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+#ifndef _DEBUG
+#define _DEBUG 0
+#endif // !_DEBUG
+#define IFD if (_DEBUG)
+typedef long long ll, i64;
+int main()
+{
+    return 0;
+}
\ No newline at end of file
diff --git a/nowcoder888/B.cpp b/nowcoder888/B.cpp
new file mode 100644
index 0000000..dd52cf5
--- /dev/null
+++ b/nowcoder888/B.cpp
@@ -0,0 +1,35 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+#ifndef _DEBUG
+#define _DEBUG 0
+#endif // !_DEBUG
+#define IFD if (_DEBUG)
+typedef long long ll, i64;
+const int N = 1e5 + 50;
+int n, a[N], cnt[N], last[N];
+int main()
+{
+    scanf("%d", &n);
+    for (int i = 1; i <= n; i++) scanf("%d", a + i);
+    ll ans = 0, cur = 0;
+    for (ll i = 1; i <= n; i++)
+    {
+        cur += cnt[i] = cnt[i - 1];
+        if (last[a[i]] == 0)
+            cnt[i]++;
+        else
+            cur -= i - last[a[i]];
+        last[a[i]] = i;
+        ans += i * cnt[i] - cur;
+    }
+    printf("%lld", ans);
+    return 0;
+}
\ No newline at end of file
diff --git a/nowcoder888/C.cpp b/nowcoder888/C.cpp
new file mode 100644
index 0000000..8503e70
--- /dev/null
+++ b/nowcoder888/C.cpp
@@ -0,0 +1,34 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+#ifndef _DEBUG
+#define _DEBUG 0
+#endif // !_DEBUG
+#define IFD if (_DEBUG)
+typedef long long ll, i64;
+const int N = 1 << 10 | 1;
+int a[N][N];
+int main()
+{
+    int n;
+    scanf("%d", &n);
+    a[0][0] = 1;
+    for (int c = 1; c < n; c <<= 1)
+        for (int i = 0; i < c; i++)
+            for (int j = 0; j < c; j++)
+            {
+                a[c + i][j] = a[i][c + j] = a[i][j];
+                a[c + i][c + j] = a[i][j] ^ 1;
+            }
+    for (int i = 0; i < n; i++)
+        for (int j = 0; j < n; j++)
+            printf("%d%c", a[i][j] * 2 - 1, " \n"[j == n - 1]);
+    return 0;
+}
\ No newline at end of file
diff --git a/nowcoder888/CMakeLists.txt b/nowcoder888/CMakeLists.txt
new file mode 100644
index 0000000..45f29f4
--- /dev/null
+++ b/nowcoder888/CMakeLists.txt
@@ -0,0 +1,16 @@
+cmake_minimum_required(VERSION 3.0)
+set(CMAKE_CXX_STANDARD 17)
+if(MSVC)
+    add_compile_options("/Zc:__cplusplus")
+endif()
+include_directories("D:\\PortableApps\\MSYS2\\mingw64\\include\\c++\\9.1.0\\x86_64-w64-mingw32")
+add_executable(A A.cpp)
+add_executable(B B.cpp)
+add_executable(C C.cpp)
+add_executable(D D.cpp)
+add_executable(E E.cpp)
+add_executable(F F.cpp)
+add_executable(G G.cpp)
+add_executable(H H.cpp)
+add_executable(I I.cpp)
+add_executable(J J.cpp)
diff --git a/nowcoder888/D.cpp b/nowcoder888/D.cpp
new file mode 100644
index 0000000..21a092b
--- /dev/null
+++ b/nowcoder888/D.cpp
@@ -0,0 +1,19 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+#ifndef _DEBUG
+#define _DEBUG 0
+#endif // !_DEBUG
+#define IFD if (_DEBUG)
+typedef long long ll, i64;
+int main()
+{
+    return 0;
+}
\ No newline at end of file
diff --git a/nowcoder888/E.cpp b/nowcoder888/E.cpp
new file mode 100644
index 0000000..2d50125
--- /dev/null
+++ b/nowcoder888/E.cpp
@@ -0,0 +1,48 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+#ifndef _DEBUG
+#define _DEBUG 0
+#endif // !_DEBUG
+#define IFD if (_DEBUG)
+typedef long long ll, i64;
+const int N = 1e5 + 50;
+struct Edge
+{
+    int nxt, to, l, r;
+} E[N];
+int adj[N], ecnt;
+inline void addEdge(int f, int t, int l, int r)
+{
+    E[++ecnt] = {adj[f], t, l, r};
+    adj[f] = ecnt;
+}
+bool modify(int u, int v, int l, int r)
+{
+    return false;
+}
+int main()
+{
+    int n, m;
+    scanf("%d%d", &n, &m);
+    for (int i = 0, f, t, l, r; i < m; i++)
+    {
+        scanf("%d%d%d%d", &f, &t, &l, &r);
+        addEdge(f, t, l, r);
+        addEdge(t, f, l, r);
+    }
+    queue<int> Q;
+    static bool inq[N];
+    for (Q.push(1), inq[1] = true; !Q.empty(); inq[Q.front()] = false, Q.pop())
+        for (int u, e = adj[u = Q.front()]; e; e = E[e].nxt)
+            if (modify(u, E[e].to, E[e].l, E[e].r) && !inq[E[e].to])
+                Q.push(E[e].to), inq[E[e].to] = true;
+    return 0;
+}
\ No newline at end of file
diff --git a/nowcoder888/F.cpp b/nowcoder888/F.cpp
new file mode 100644
index 0000000..21a092b
--- /dev/null
+++ b/nowcoder888/F.cpp
@@ -0,0 +1,19 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+#ifndef _DEBUG
+#define _DEBUG 0
+#endif // !_DEBUG
+#define IFD if (_DEBUG)
+typedef long long ll, i64;
+int main()
+{
+    return 0;
+}
\ No newline at end of file
diff --git a/nowcoder888/G.cpp b/nowcoder888/G.cpp
new file mode 100644
index 0000000..0a8ae53
--- /dev/null
+++ b/nowcoder888/G.cpp
@@ -0,0 +1,53 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+#ifndef _DEBUG
+#define _DEBUG 0
+#endif // !_DEBUG
+#define IFD if (_DEBUG)
+typedef long long ll, i64;
+const int N = 1e5 + 50;
+char s[N];
+int main()
+{
+    scanf("%s", s);
+    int n = strlen(s), ans = 0;
+    list<char> l(s, s + n);
+    for (auto ite = l.begin(); ite != l.end();)
+    {
+        bool flag = true;
+        auto ite2 = ite;
+        ++ite2;
+        if (ite2 != l.end() && *ite2 == *ite)
+        {
+            auto ite3 = ite2;
+            ++ite3;
+            if (ite3 != l.end() && *ite3 == *ite)
+            {
+                flag = false;
+                ans++;
+                if (ite == l.begin())
+                {
+                    l.erase(ite, ++ite3);
+                    ite = l.begin();
+                }
+                else
+                {
+                    l.erase(ite--, ++ite3);
+                    if (ite != l.begin()) --ite;
+                }
+            }
+        }
+        if (flag && ite != l.end())
+            ++ite;
+    }
+    printf("%d", ans);
+    return 0;
+}
\ No newline at end of file
diff --git a/nowcoder888/H.cpp b/nowcoder888/H.cpp
new file mode 100644
index 0000000..21a092b
--- /dev/null
+++ b/nowcoder888/H.cpp
@@ -0,0 +1,19 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+#ifndef _DEBUG
+#define _DEBUG 0
+#endif // !_DEBUG
+#define IFD if (_DEBUG)
+typedef long long ll, i64;
+int main()
+{
+    return 0;
+}
\ No newline at end of file
diff --git a/nowcoder888/I.cpp b/nowcoder888/I.cpp
new file mode 100644
index 0000000..21a092b
--- /dev/null
+++ b/nowcoder888/I.cpp
@@ -0,0 +1,19 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+#ifndef _DEBUG
+#define _DEBUG 0
+#endif // !_DEBUG
+#define IFD if (_DEBUG)
+typedef long long ll, i64;
+int main()
+{
+    return 0;
+}
\ No newline at end of file
diff --git a/nowcoder888/J.cpp b/nowcoder888/J.cpp
new file mode 100644
index 0000000..21a092b
--- /dev/null
+++ b/nowcoder888/J.cpp
@@ -0,0 +1,19 @@
+#define _CRT_SECURE_NO_WARNINGS
+#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
+#include <bits/stdc++.h>
+using namespace std;
+#define CRP(t, x) const t &x
+#define OPL(t, x) bool operator<(CRP(t, x)) const
+#define FIL(x, v) memset(x, v, sizeof(x))
+#define CLR(x) FIL(x, 0)
+#define NE1(x) FIL(x, -1)
+#define INF(x) FIL(x, 0x3f)
+#ifndef _DEBUG
+#define _DEBUG 0
+#endif // !_DEBUG
+#define IFD if (_DEBUG)
+typedef long long ll, i64;
+int main()
+{
+    return 0;
+}
\ No newline at end of file