51 lines
1.0 KiB
C++
51 lines
1.0 KiB
C++
#include <bits/stdc++.h>
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using namespace std;
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const int N = 110;
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const int INF = 0x3f3f3f3f;
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int n, k;
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int w[N], h[N];
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int tmax = -INF;
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/*
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2 6
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4 3
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5 4
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答案：
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2
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*/
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// 检查x是否满足某种性质
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bool check(int x) {
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int cnt = 0;
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for (int j = 1; j <= n; j++)
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cnt += (w[j] / x) * (h[j] / x);
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//以2为例，cnt=6 k=6 正合适
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//以1为例 cnt=32 k=6 cnt>k
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//所以最终的限制条件为cnt<=k
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return cnt <= k;
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}
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int main() {
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cin >> n >> k;
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for (int i = 1; i <= n; i++) {
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cin >> w[i] >> h[i];
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tmax = max(min(w[i], h[i]), tmax);
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}
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//二分查询
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int l = 1, r = tmax;
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while (l < r) {
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int mid = l + r >> 1;
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if (check(mid))
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r = mid;
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else
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l = mid + 1;
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}
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//也可能找不到答案
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int cnt = 0;
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for (int i = 1; i <= n; i++)
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cnt += (w[i] / l) * (h[i] / l);
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if (cnt < k)
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cout << -1 << endl;
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else
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cout << l << endl;
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return 0;
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} |