放假了心血来潮，水几个题

OnlineJudges/Codeforces/CF864/CMakeLists.txt

@@ -0,0 +1,4 @@
+add_executable(a a.cpp)
+add_executable(b b.cpp)
+add_executable(c c.cpp)
+add_executable(d d.cpp)

OnlineJudges/Codeforces/CF864/a.cpp

@@ -0,0 +1,15 @@
+#include <algorithm>
+#include <cstdio>
+int n, arr[100];
+int main()
+{
+    scanf("%d", &n);
+    for (int i = n; i--;)
+        scanf("%d", arr + i);
+    std::sort(arr, arr + n);
+    if (arr[0] == arr[(n >> 1) - 1] && arr[n >> 1] == arr[n - 1] && arr[0] != arr[n - 1])
+        printf("YES\n%d %d", arr[0], arr[n - 1]);
+    else
+        puts("NO");
+    return 0;
+}

OnlineJudges/Codeforces/CF864/b.cpp

@@ -0,0 +1,19 @@
+#include <algorithm>
+#include <cctype>
+#include <cstdio>
+#include <set>
+int n;
+char str[201];
+int main()
+{
+    scanf("%d%s", &n, str);
+    std::set<char> S;
+    int ans = 0;
+    for (int pos = 0; pos <= n; pos++)
+        if (islower(str[pos]))
+            S.insert(str[pos]);
+        else
+            ans = std::max(ans, static_cast<int>(S.size())), S.clear();
+    printf("%d", ans);
+    return 0;
+}

OnlineJudges/Codeforces/CF864/c.cpp

@@ -0,0 +1,13 @@
+#include <cstdio>
+int main()
+{
+    int a, b, f, k, r, ans = 0;
+    for (scanf("%d%d%d%d", &a, &b, &f, &k), r = b; k--; f = a - f)
+        if (r < f || b < a - f)
+            return puts("-1"), 0;
+        else if (r >= a + (k ? a - f : 0))
+            r -= a;
+        else
+            ans++, r = b - a + f;
+    return printf("%d", ans), 0;
+}

OnlineJudges/Codeforces/CF864/d.cpp

@@ -0,0 +1,28 @@
+#include <cctype>
+#include <cstdio>
+inline void readint(int &x)
+{
+    int ch = x = 0;
+    while (!isdigit(ch = getchar())) 0;
+    for (; isdigit(ch); ch = getchar()) x = x * 10 + ch - '0';
+}
+const int N = 200020;
+int arr[N], cnt[N], n, ans;
+bool used[N];
+int main()
+{
+    readint(n);
+    for (int i = 0; i < n; i++) readint(arr[i]), ans += cnt[arr[i]]++ > 0;
+    printf("%d\n", ans);
+    for (int i = 0, x = 1; i < n; i++)
+        if (cnt[arr[i]] > 1)
+        {
+            while (cnt[x]) x++;
+            if (arr[i] > x || used[arr[i]])
+                cnt[arr[i]]--, cnt[arr[i] = x]++;
+            else
+                used[arr[i]] = true;
+        }
+    for (int i = 0; i < n; i++) printf("%d ", arr[i]);
+    return 0;
+}