BellmanFord C++(模板)

/*******************************************************************************
* Name: BellmanFord
* Description : Find the shortest path from the start point to all other points
* Parameter list: edge - adjacency matrix of the graph
*                 dist - array of the shortest distance from start point
*                 path - array of the shortest path
*                 order - the number of the vertex
*                 start - start point
*                 maxNum - max distance means there is no path
********************************************************************************/

void BellmanFord(int *edge, int *dist, int *path, const int order, const int start, const int maxNum)
{
    for (int i = 0; i < order; i++)
    {
        dist[i] = *(edge + start * order + i);
        if (dist[i] < maxNum && i != start)
            path[i] = start;
        else
            path[i] = -1;
    }
    bool isChanged = true;

    for (int k = 2; (k < order) && isChanged; k++)
    {
        isChanged = false;
        for (int i = 0; i < order; i++)
        {
            for (int j = 0; j < order; j++)
            {
                if (dist[i] > dist[j] + *(edge + j * order + i))
                {
                    dist[i] = dist[j] + *(edge + j * order + i);
                    path[i] = j;
                    isChanged = true;
                }
            }
        }
    }
}

调用示例:

    const int maxNum = 1e8;
    int edge[7][7] = 
    {
        {0, 6, 5, 5, maxNum, maxNum, maxNum},
        {maxNum, 0, maxNum, maxNum, -1, maxNum, maxNum},
        {maxNum, -2, 0, maxNum, 1, maxNum, maxNum},
        {maxNum, maxNum, -2, 0, maxNum, -1, maxNum},
        {maxNum, maxNum, maxNum, maxNum, 0, maxNum, 3},
        {maxNum, maxNum, maxNum, maxNum, maxNum, 0, 3},
        {maxNum, maxNum, maxNum, maxNum, maxNum, maxNum, 0}
    };
    int dist[7];
    int path[7];
    BellmanFord((int*)edge, dist, path, 7, 0, maxNum);