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75 lines
1.9 KiB
C++
75 lines
1.9 KiB
C++
#define _CRT_SECURE_NO_WARNINGS
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#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
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#include <bits/stdc++.h>
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using namespace std;
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#define C(x) ((x) = getchar())
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#define L(x) ((x) << 1)
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#define R(x) ((x) << 1 | 1)
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#define avg(x, y) (((x) + (y)) >> 1)
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typedef long long i64;
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inline void read(int &x)
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{
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/*int ch = x = 0, sign = 1;
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while (!isdigit(C(ch)))
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if (ch == '-') sign = -1;
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for (; isdigit(ch); C(ch))
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x = x * 10 + ch - '0';
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x *= sign;*/
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scanf("%d", &x);
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}
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const int N = 400500;
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int a[N], arr[N << 2];
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void build(int k, int l, int r)
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{
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if (l == r - 1) return void(arr[k] = a[l]);
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int m = avg(l, r);
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build(L(k), l, m);
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build(R(k), m, r);
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arr[k] = max(arr[L(k)], arr[R(k)]);
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}
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void modify(int k, int l, int r, int x, int y, int v)
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{
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if (x <= l && r <= y)
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return void(arr[k] = v);
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int m = avg(l, r);
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if (x < m) modify(L(k), l, m, x, y, v);
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if (y > m) modify(R(k), m, r, x, y, v);
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arr[k] = max(arr[L(k)], arr[R(k)]);
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}
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int query(int k, int l, int r, int x, int y)
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{
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if (x <= l && r <= y)
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return arr[k];
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int m = avg(l, r);
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int res = 0;
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if (x < m) res = max(res, query(L(k), l, m, x, y));
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if (y > m) res = max(res, query(R(k), m, r, x, y));
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return res;
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}
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int main()
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{
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int n, m;
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while (~scanf("%d%d", &n, &m))
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{
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memset(a, 0, sizeof a);
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memset(arr, 0, sizeof arr);
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for (int i = 0; i < n; i++) read(a[i]);
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build(1, 0, n);
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while (m--)
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{
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int op = 0, x, y, z;
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while (op != 'U' && op != 'Q') C(op);
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if (op == 'Q')
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{
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read(x), read(y);
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printf("%d\n", query(1, 0, n, x - 1, y));
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}
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else
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{
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read(x), read(z);
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modify(1, 0, n, x - 1, x, z);
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}
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}
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}
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return 0;
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} |