poj 1734 Sightseeing trip_ 最小环记录路径

#include <iostream>
#include<cstdio>
using namespace std;
#define N 110
#define INF 0xffffff
int map

,n,m,dist

,pre

,path
;
/* run this program using the console pauser or add your own getch, system("pause") or input loop */
void floyd(){
int i,j,k,ans=INF,num,p;
for(i=0;i<=n;i++)
for(j=0;j<=n;j++)
dist[i][j]=map[i][j];
for(k=1;k<=n;k++){
for(i=1;i<k;i++)
for(j=i+1;j<k;j++){
int tmp=dist[i][j]+map[i][k]+map[k][j];
if(tmp<ans){
ans=dist[i][j]+map[i][k]+map[k][j];
p=j;
num=0;
while(p!=i){
path[num++]=p;
p=pre[i][p];
}
path[num++]=i;
path[num++]=k;
}
}

for(i=1;i<=n;i++)
for(j=1;j<=n;j++){
int tmp=dist[i][k]+dist[k][j];
if(dist[i][j]>dist[i][k]+dist[k][j]){
dist[i][j]=dist[i][k]+dist[k][j];
pre[i][j]=pre[k][j];
}
}
}
if(ans==INF)
printf("No solution.\n");
else{
printf("%d",path[0]);
for(i=1;i<num;i++)
printf(" %d",path[i]);
puts("");
}
}
int main(int argc, char** argv) {
int i,j,a,b,d;
//	freopen("in.txt","r",stdin);
while(scanf("%d%d",&n,&m)!=EOF){
for(i=1;i<=n;i++)
for(j=1;j<=n;j++){
map[i][j]=INF;
pre[i][j]=i;
}
for(i=0;i<m;i++){
scanf("%d%d%d",&a,&b,&d);
if(map[a][b]>d)
map[a][b]=map[b][a]=d;
}
floyd();
}
return 0;
}