王道考研 ++++ Floyd 弗洛伊德算法

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

#define MaxSize 100
#define INF 1000001

int Graph[MaxSize][MaxSize];
/*弗洛伊德算法*/
void Floyd(int n)
{
  int i,j,k;
  //依次比较找出两个点之间的最短距离
  for(k = 0;k < n;k++)
    for(i = 0;i < n;i++)
      for(j = 0;j < n;j++)
        if(Graph[i][k] != INF && Graph[k][j] != INF && Graph[i][k] + Graph[k][j] < Graph[i][j])
          Graph[i][j] = Graph[i][k] + Graph[k][j];
}
int main(int argc, char const *argv[]) {
  int n,m,flag,i,j;

  for(i = 0;i < n;i++)
    for(j = 0;j < n;j++)
      Graph[i][j] = INF;
  //自己到自己为0
  for(i = 0;i < n;i++)Graph[i][i] = 0;
  printf("有向图-1 | 无向图-2:");
  scanf("%d",&flag);
  printf("请输入节点个数和边数:");
  scanf("%d%d",&n,&m);
  printf("请输入%d条边:\n",m);
  for(i = 0;i < m;i++)
  {
    int a,b,len;
    scanf("%d%d%d",&a,&b,&len);
    Graph[a][b] = len;
    if(flag == 2)
    {
      Graph[b][a] = len;
    }
  }
  Floyd(n);
  printf("-----------\n");
  for(i = 0;i < n;i++)
  {
    for(j = 0;j < n;j++)
    {
      if(Graph[i][j] != INF)
        printf("%d -> %d: %d |\n",i,j,Graph[i][j]);
    }
    printf("-----------\n");
  }
  return 0;
}