Dijkstra算法——单源最短路径

两种最常见的最短路径问题之一：求某个源点到其余各项顶点的最短路径

代码

#include <stdio.h>
int main()
{
    int e[10][10], dis[10], book[10], i, j, n, m, t1, t2, t3, u, v, min;
    int inf = 99999999; //正无穷值
    //读入n和m，n表示顶点个数，m表示边的条数
    scanf("%d %d", &n, &m);

    //初始化
    for (i = 1; i <= n; i++)
        for (j = 1; j <= n; j++)
            if (i == j) e[i][j] = 0;
            else e[i][j] = inf;

    //读入边
    for (i = 1; i <= m; i++)
    {
        scanf("%d %d %d", &t1, &t2, &t3);
        e[t1][t2] = t3;
    }

    //初始化dis数组，这里是1号顶点到其余各个顶点的初始路程
    for (i = 1; i <= n; i++)
        dis[i] = e[1][i];

    //book数组初始化
    for (i = 1; i <= n; i++)
        book[i] = 0;
    book[i] = 1;

    //Dijkstra算法核心语句
    for (i = 1; i <= n - 1; i++)
    {
        //找到离1号顶点最近的顶点
        min = inf;
        for (j = 1; j <= n; j++)
        {
            if (book[j] == 0 && dis[j] < min)
            {
                min = dis[j];
                u = j;
            }
        }

        book[u] = 1;

        for (v = 1; v <= n; v++)
        {
            if (e[u][v] < inf)
            {
                if (dis[v] > dis[u] + e[u][v])
                    dis[v] = dis[u] + e[u][v];
            }
        }
    }

    //输出最终的结果
    for (i = 1; i <= n; i++)
    {
        printf(" %d ", dis[i]);
    }

    getchar();
    getchar();
    return 0;
}