Floyd-Warshall算法（有向图）

#include<stdio.h>
#include<malloc.h>
#include<string.h>
#include<stack>
using namespace std;
#define MAX_VERTEX_NUM 20
#define INFINITY 32768
int visited[100];
typedef struct node1
{
	int adj;
}gra;
typedef struct node2
{
	gra arcs[100][100];
	int vertex[100];
	int vexnum,arcnum;
}*graph,graph1;
int locatevertex(graph &g,int v)
{
	int j=0,k;
	for(k=0;k<g->vexnum;k++)
	{
		if(g->vertex[k]==v)
		{
			j=k;
			break;
		}	
	}
	return j;
}
void create(graph &g)
{
	int i,j,k,v1,v2,weight;
	printf("请输入图的最大顶点数和最大弧数: ");
	scanf("%d%d",&g->vexnum,&g->arcnum);
	for(i=0;i<g->vexnum;i++)
	{
		for(j=0;j<g->vexnum;j++)
		{
			if(i==j)
			g->arcs[i][j].adj=0;
			else
			g->arcs[i][j].adj=INFINITY;
		}
	}
	printf("请输入图的各顶点值: ");
	for(i=0;i<g->vexnum;i++)
		scanf("%d",&g->vertex[i]);
	for(k=0;k<g->arcnum;k++)
	{
		printf("请输入两顶点1,2表示1到2有关系: ");
		scanf("%d%d%d",&v1,&v2,&weight);
		i=locatevertex(g,v1);
		j=locatevertex(g,v2);
		g->arcs[i][j].adj=weight;
	}
}
void shortestpath(graph &g,int n1,int n2)
{
	int k;
	int dist[MAX_VERTEX_NUM][MAX_VERTEX_NUM];
	for(int i=0;i<g->vexnum;i++)
	{
		for(int j=0;j<g->vexnum;j++)
		{
		dist[i][j]=g->arcs[i][j].adj;
        }
	}
	for(k=0;k<g->vexnum;k++)
	{
	   for(i=0;i<g->vexnum;i++)
	   {
		   for(int j=0;j<g->vexnum;j++)
		   {
			   if(dist[i][k]+dist[k][j]<dist[i][j])
			   dist[i][j]=dist[i][k]+dist[k][j];
		   }
	   }
	}
    n1=locatevertex(g,n1);
	n2=locatevertex(g,n2);
	printf("最短路径长度为: ");
	printf("%d\n",dist[n1][n2]);
}
int main()
{
	graph g;
	int n1,n2;
	g=(graph)malloc(sizeof(graph1));
	create(g);
	printf("请输入两个顶点求出它们之间的最短路径: ");
	scanf("%d%d",&n1,&n2);
	shortestpath(g,n1,n2);
	return 0;
}