背包九讲之九：背包问题求具体方案

 1 #include<iostream>
 2 #include<algorithm>
 3 using namespace std;
 4 const int n = 1002;
 5 int N, V, v[n], w[n], f[n][n];
 6 int main() {
 7        cin >> N >> V;
 8        for (int i = 1; i <= N; ++i)
 9               cin >> v[i] >> w[i];
10        for (int i = N; i >= 1; --i)       //倒着排，方便正着输出物品序号
11               for (int j = 0; j <= V; ++j) {
12                      f[i][j] = f[i + 1][j];
13                      if (j >= v[i])
14                            f[i][j] = max(f[i][j], f[i + 1][j - v[i]] + w[i]);
15               }
16        int vol = V;
17        for (int i = 1; i <= N; ++i)       //正着输出物品序号
18               if (vol >= v[i] && f[i][vol] == f[i + 1][vol - v[i]] + w[i]) {
19                      cout << i << " ";
20                      vol -= v[i];
21               }
22 }