POJ 3259 Wormholes

类似于 POJ1860 求解负权回路问题，不过考虑到图可能不连通，所以需添加一个超级节点，与各顶点的初始距离均为1000

 

#include <iostream>
using namespace std;

int main()
{
    int F, N , M, W, S, E, T;
    int path[5300][3];
    int dist[501];
    cin >> F;
    while (F--)
    {
        cin >> N >> M >> W;
        int size = 0;
        for (int i = 0; i < M; i++)
        {
            cin >> S >> E >> T;
            path[size][0] = S;
            path[size][1] = E;
            path[size++][2] = T;

            path[size][0] = E;
            path[size][1] = S;
            path[size++][2] = T;
        }
        for (int i = 0; i < W; i++)
        {
            cin >> S >> E >> T;
            path[size][0] = S;
            path[size][1] = E;
            path[size++][2] = -T;
        }
        fill(&dist[0], &dist[N], 1000);

        bool isChanged = true;
        for (int i = 0; i < N && isChanged; i++)
        {
            isChanged = false;
            for (int j = 0; j < size; j++)
            {
                if (dist[path[j][1]] > dist[path[j][0]] + path[j][2])
                {
                    dist[path[j][1]] = dist[path[j][0]] + path[j][2];
                    isChanged = true;
                }
            }
        }
        cout << (isChanged ? ("YES") : ("NO")) << endl;
    }
    return 0;
}