弗洛伊德算法

#include<iostream>
using namespace std;
#define maxSize 99
#define inf 999
typedef struct
{
	int no;
	char info;
}VertexType;
typedef struct
{
	int edges[maxSize][maxSize];
	int n,e;
	VertexType vex[maxSize];
}MGraph;
void printPath(int u,int v,int path[][maxSize])
{
	if(path[u][v]==-1)
		cout<<v<<" ";
	else
	{
		int mid=path[u][v];
		printPath(u,mid,path);
		printPath(mid,v,path);	
	} 
}
void Floyd(MGraph g,int path[][maxSize])
{
	int i,j,k;
	int A[maxSize][maxSize];
	for(int i=0;i<g.n;++i)
		for(int j=0;j<g.n;++j)
		{
			A[i][j]=g.edges[i][j];
			path[i][i]=-1;
		}
	for(int k=0;k<g.n;++k)
		for(int i=0;i<g.n;++i)
			for(int j=0;j<g.n;++j)
			if(A[i][j]>A[i][k]+A[k][j])
			{
				A[i][j]=A[i][k]+A[k][j];
				path[i][j]=k;
			}
}
/*4 8 
0 1 5 0 3 7
1 2 4 1 3 2
2 0 3 2 1 3 2 3 2
3 2 1*/
int main()
{
	MGraph g;
	int path[maxSize][maxSize];
	cin>>g.n>>g.e;
	for(int i=0;i<g.n;++i)
		for(int j=0;j<g.n;++j)
		{
			path[i][j]=-1;
			g.edges[i][j]=inf;
			if(i==j)
			g.edges[i][j]=0;
		}
	

	for(int i=0;i<g.e;++i)
		{
			int u,v,w;
			cin>>u>>v>>w;
			g.edges[u][v]=w;
		}
	Floyd(g,path);
	int u=1,v=0;
	cout<<"最短路徑爲："<<endl<<u<<" ";
	printPath(u,v,path);
}