Minimum Spanning Tree Template

prim algorithm:

int prim(int n, int sta)//n means there are n vertices, and the sta table generates the minimum spanning tree from the sta vertex
{
    int mark[M],dis[M];
    int i,sum = 0; //sum is the total minimum spanning tree edge weight
    for (i = 0;i < n;i++) //Initialize the weights of the dis[i] table from vertex sta to point i
    {
        dis [i] = mat [sta] [i];
        mark[i] = 0;
    }
    mark[sta] = 1; //sta this vertex is added to the minimum spanning tree
    for (i = 1;i < n;i++) //loop n-1 times, each time find a graph with n points on the edge of the minimum weight
    { //Only n-1 edges
        int min = inf; //inf table infinity
        for (j = 0;j < n;j++)//Find the vertex that is not currently in the minimum spanning tree with the smallest edge weight
            if (!mark[j] && dis[j] < min)
                min = dis[j], flag = j;
        mark[flag] = 1; //Add the vertex to the minimum spanning tree
        sum += dis[flag]; //sum plus its edge weight
        for (j = 0;j < n;j++) //Update from flag to each point is the minimum weight
            if (dis[j] > mat[flag][j])
                dis[j] = mat[flag][j];
    }
    return sum; //return the sum of edge weights
}