Bellman无向图

Bellman无向图

#include
#include
#include
#include
#include
#include
#include
#include
#include
using namespace std;
const int INF=0x3f3f3f3f;
const int N=500;
struct edge{
    int head;
    int tail;
    int cost;
}edge[N];
int graph[N][N];
int check[N];
int dis[N];
int n,m;
void Bellman()
{
    int i,p,j;
    int check;
    for(i=1;i<=n;i++)
        dis[i]=(i==1?0:INF);
    for(i=1;i<=n-1;i++)
    {
        check=0;
        for(j=1;j<=2*m;j++)
            if(dis[edge[j].tail]>dis[edge[j].head]+edge[j].cost)
            {
                dis[edge[j].tail]=dis[edge[j].head]+edge[j].cost;
                check=1;
            }
        if(check==0)
            break;
    }
    /*此处应添加判断负权环的代码*/
    /*此处应添加判断负权环的代码*/
    /*此处应添加判断负权环的代码*/
    /*此处应添加判断负权环的代码*/
}
int main()
{
    int i,p,j;
    int a,b,c;
    while(scanf("%d%d",&n,&m)!=EOF)
{
    if(n==0&&m==0)
        break;
    for(i=1;i<=2*m;i++)
    {
        scanf("%d%d%d",&edge[i].head,&edge[i].tail,&edge[i].cost);
        i++;
        edge[i].head=edge[i-1].tail;
        edge[i].tail=edge[i-1].head;
        edge[i].cost=edge[i-1].cost;
    }
    Bellman();
    printf("%d\n",dis[n]);
}
    return 0;
}