Algorithm-Renewed

2025-09-13 22:37:17 +08:00
parent 265b8af720
commit 7b6acef275
14 changed files with 778 additions and 1 deletions
--- a/【深基12.例1】部分背包问题.cpp
+++ b/【深基12.例1】部分背包问题.cpp
@@ -0,0 +1,46 @@
+#include <iostream>
+#include <tuple>
+#include <vector>
+#include <iomanip>
+#include <algorithm>
+using namespace std;
+
+struct cmp {
+    bool operator()(const tuple<double, double, double>& a,
+                    const tuple<double, double, double>& b) const {
+        return get<2>(a) > get<2>(b); // <20><><EFBFBD>Լ۱Ƚ<DBB1><C8BD><EFBFBD>
+    }
+};
+
+int main() {
+    int n;
+    double t;
+    cin >> n >> t;
+
+    vector<tuple<double, double, double>> arr(n);
+    for (int i = 0; i < n; i++) {
+        double a, b;
+        cin >> a >> b;
+        arr[i] = make_tuple(a, b, b / a); // (<28><><EFBFBD><EFBFBD>, <20><>ֵ, <20><>λ<EFBFBD><CEBB>ֵ)
+    }
+
+    sort(arr.begin(), arr.end(), cmp());
+
+    double value = 0;
+    int p = 0;
+
+    while (t > 0 && p < n) {
+        if (t >= get<0>(arr[p])) {
+            value += get<1>(arr[p]);       // ȡ<><C8A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ʒ
+            t -= get<0>(arr[p]);           // <20>ȼ<EFBFBD><C8BC><EFBFBD>ǰ<EFBFBD><C7B0><EFBFBD><EFBFBD>
+            p++;
+        } else {
+            value += t * get<2>(arr[p]);   // ȡһ<C8A1><D2BB><EFBFBD><EFBFBD>
+            break;
+        }
+    }
+
+    cout << fixed << setprecision(2) << value << endl;
+    return 0;
+}
+