dijkstra算法求最短路

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define  MAXINT  32767
#define  MAXNUM  6

char *str = "ABCDEF";
void dijkstra(int *dist, int *prev, int (*A)[MAXNUM], int v0);
void findPath(int *dist, int *prev, int start, int end);

int main()
{

    
    int A[MAXNUM][MAXNUM] = {{0, 6, 3, MAXINT, MAXINT, MAXINT}, 
                             {6, 0, 2, 5,      MAXINT, MAXINT},
                             {3, 2, 0, 3,      4,      MAXINT},
                             {MAXINT, 5, 3, 0, 2,           3},
                             {MAXINT, MAXINT, 4, 2, 0,      5},
                             {MAXINT, MAXINT, MAXINT, 3, 5, 0},
                            };
    int dist[MAXNUM] = {0};
    int prev[MAXNUM] = {0};
    int v0 = 2, i = 0;
    
    dijkstra(dist, prev, A, v0);
    
    findPath(dist, prev, v0, 5);
    
    //for(i = 0; i < MAXNUM; i++)
    {
    //    printf("%d ", prev[i]);
    }
        
    system("pause");
    return 0;
}

void findPath(int *dist, int *prev, int start, int end)
{
    int tmp = prev[end];
    int *rst = (int*)calloc(MAXNUM, sizeof(int));
    int cnt = 0, i = 0;
    rst[cnt] = end;
    cnt++; 
    if(tmp == start)
    {
        rst[cnt] = tmp;
    }
    else
    {
        while(tmp != start)
        {   
            rst[cnt] = tmp;
            tmp = prev[tmp];
            cnt++;    
        }
        rst[cnt] = tmp;
    }
    
    //printf("%d\n", cnt);
    for(i = cnt; i >= 0; i--)
    {
        printf("%c", str[rst[i]]);
        if(i != 0)
        {
            printf("->");
        }
    }
    printf("  %d\n", dist[end]);
    
    free(rst);
    rst = NULL;
        
}

void dijkstra(int *dist, int *prev, int (*A)[MAXNUM], int v0)
{
    int S[MAXNUM];
    int n = MAXNUM, i = 0, j = 0;
    for (i = 0; i < n; i++)
    {
        dist[i] = A[v0][i];
        S[i] = 0;
        if(dist[i] == MAXINT)
        {
            prev[i] = -1;
        }
        else
        {
            prev[i] = v0;
           // printf("%c前驱%c\n", str[i], str[v0]);
        }
    }
    dist[v0] = 0;
    S[v0] = 1;
    
    for(i = 1; i < n; i++)
    {
        int mindist = MAXINT;
        int u = v0;
        for(j = 0; j < n; j++)
        {
            if((!S[j]) && dist[j] < mindist)
            {
                u = j;
                mindist = dist[j];
            } 
        }
        S[u] = 1;
        
        for(j = 0; j < n; j++)
        {
            if((!S[j]) && A[u][j] < MAXINT)
            {
                if(dist[u] + A[u][j] < dist[j])
                {
                    dist[j] = dist[u] + A[u][j];
                    prev[j] = u;
                   // printf("%c前驱%c\n", str[j], str[u]);
                }
            }
        }
    }
}