Bellman-Ford algorithm

[zagiza]

Hi;) I have small problem with my code(Bellman-Ford algorithm). I don't have any idea why it's not working, maybe it can be a small mistake, but I'm just a beginner. Can you help me with it?

#include<cstdio>
#include<vector>
using namespace std;
int n, m, s; 
vector<vector<int> >E;
vector<int>D;
const int INF = (1 << 30); 
int main()
{
    scanf("%d %d %d", &n, &m, &s); 
    E.resize(m);
    for (int i = 0; i < m; i++) 
    {
        int a , b, c;
        scanf("%d %d %d", &a, &b, &c);
        E[i].resize(3);
        E[i][0] = a;
        E[i][1] = b;
        E[i][2] = c;
    }
    D.resize(n);
    for (int i = 0; i < n; i++) D[i]=INF;      
        D[s] = 0; 
    for (int i = 1; i<=n; i++)
    {
        for (int j = 0; j < m; j++)
        {
            int a = E[j][0], b = E[j][1], c = E[j][2];
            if (D[a]!=INF && D[a] < D[b]-c) 
            {
                D[b] = D[a]+c; 
                if (i==n)
                {
                    printf("NO"); 
                    return 0;
                }
            }
        }
     }
     for (int i = 0; i < m; i++)
     {
        if (i!=s && D[i]<INF)
        {
                 printf("%d %d\n", i, D[i]); 
        }
        return 0;
     }
}

[leppyr64]

Please surround your code with the code tags. It preserves your indentation.

[leppyr64]

There's nothing obviously wrong with that. Are you trying to solve a specific problem?

How do you know that it's not working?

[zagiza]

Because i didn't see the answer, sth wrong with the last loop. And when I put it on spoj.pl it's tells me "wrong answer". I'm trying to solve "the shortest path" problem.

[leppyr64]

Post your entire code for the problem.

O(n*m) is not likely going to pass the timelimit even if you do solve your WA.

[zagiza]

This is my entire code.

[leppyr64]

Post a link to the problem statement because this code doesn't come close to solving the problem listed as SHPATH.