'commit'

TangDou/LanQiaoBei/LanQiaoBei13ShengSai_ZJ_I/BC4_ErFen.cpp

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