#149. 01 分数规划

https://loj.ac/s/1630402

LibreOJ/149/149.cpp

@@ -0,0 +1,60 @@
+#include <iostream>
+#include <algorithm>
+#include <iomanip>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 1e5 + 5;
+const double eps = 1e-7;
+
+int n, k, a[N], b[N];
+double c[N];
+
+inline bool check(double mid) {
+    double sum = 0;
+
+    for (int i = 1; i <= n; i++) {
+        c[i] = static_cast<double>(a[i]) - mid * b[i];
+    }
+
+    std::sort(c + 1, c + 1 + n, std::greater<>());
+
+    for (int i = 1; i <= k; i++) {
+        sum += c[i];
+    }
+
+    return sum >= 0;
+}
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n >> k;
+
+    for (int i = 1; i <= n; i++) {
+        cin >> a[i];
+    }
+
+    for (int i = 1; i <= n; i++) {
+        cin >> b[i];
+    }
+
+    double l = 0, r = 1e9;
+
+    while (r - l > eps) {
+        double mid = (l + r) / 2;
+
+        if (check(mid)) {
+            l = mid;
+        } else {
+            r = mid;
+        }
+    }
+
+    cout << std::fixed << std::setprecision(4) << l << endl;
+
+    return 0;
+}