'commit'

TangDou/AcWing/MinusCircle/POJ2976.cpp

@@ -0,0 +1,41 @@
+#include <cstdio>
+#include <iostream>
+#include <algorithm>
+#include <cmath>
+
+using namespace std;
+const int N = 1010;
+const int INF = 0x3f3f3f3f;
+int n, k;
+int a[N], b[N];
+const double eps = 1e-8;
+
+double d[N];
+
+bool check(double x) {
+    for (int i = 0; i < n; i++) d[i] = a[i] - x * b[i];
+    sort(d, d + n, greater<double>()); //由大到小排序
+
+    double sum = 0;
+    for (int i = 0; i < n - k; i++) sum += d[i];
+    return sum >= 0; //从大到小选n-k个，看ans是否为可行的解
+}
+
+int main() {
+    while (cin >> n >> k && (n || k)) {
+        for (int i = 0; i < n; i++) cin >> a[i];
+        for (int i = 0; i < n; i++) cin >> b[i];
+
+        //浮点数二分
+        double l = 0, r = INF;
+        while (r - l > eps) {
+            double mid = (l + r) / 2; //注意浮点数不能用右移操作
+            if (check(mid))
+                l = mid; //向右逼近，使结果更大一些
+            else
+                r = mid; //向左逼近，使结果更小一些
+        }
+        printf("%.0lf\n", l * 100); // 四舍五入
+    }
+    return 0;
+}