uva 624 CD (0-1背包打印路径)

#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <vector> 
using namespace std;
const int inf = 1000000;
#define N 1000000 
int dp[22]
;
int a[22];
int n, t; 
void printf_path(vector<int>& v, int c) 
{
        for (int i = t; i > 0; i--)
             if (dp[i - 1][c] !=  dp[i][c])
             {
                      v.push_back(i);
                      c -= a[i];
             }
             
        for (int i = v.size() - 1; i >= 0; i--)
             printf("%d ", a[v[i]]);
} 
int main()
{
     while (scanf("%d", &n) != EOF)
     {
           scanf("%d", &t);
           for (int i = 0; i <= n; i++)dp[0][i] = 0;
           for (int i = 1; i <= t; i++)
           {
               scanf("%d", a + i);
           }
           for (int i = 1; i <= t; i++)
           { 
              for (int j = 1; j < a[i]; j++)dp[i][j] = dp[i -1][j]; 
              for (int j = a[i]; j <= n; j++)
              { 
                 dp[i][j] = max(dp[i - 1][j], dp[i - 1][j - a[i]] + a[i]);
              }
              //for (int k = 0; k <= n; k++)printf("%d ", dp[i][k]);puts("");
           } 
           vector<int> v;      
           printf_path(v, dp[t]
); 
           printf("sum:%d\n", dp[t]
);
     }
     return 0;
}