HDU1385 Minimum Transport Cost（最短路输出路径）

#include <iostream>
#include <cstdio>
#include <cstring>
#include <string>
#include <queue>
#include <cmath>
#include <vector>
#include <algorithm>
using namespace std;
#define maxn 1005
#define inf 1e8
int a[maxn][maxn],tax[maxn],dis[maxn],fa[maxn],ans[maxn],n,x,y,temp;
bool vis[maxn];
void spfa()
{
memset(vis,false,sizeof(vis));
for(int i=1;i<=n;i++)
{
dis[i]=fa[i]=inf;
vis[i]=false;
}
dis[y]=0;
queue<int>q;
q.push(y);
vis[y]=true;
while(!q.empty())
{
temp=q.front();
q.pop();
for(int i=1;i<=n;i++)
{
if(-1==a[i][temp]||i==temp) continue;
else
{
if(dis[temp]+tax[i]+a[i][temp]<dis[i])
{
dis[i]=dis[temp]+tax[i]+a[i][temp];
fa[i]=temp;
if(vis[i]==false)
{
q.push(i);
vis[i]=true;
}
}
else if(dis[temp]+tax[i]+a[i][temp]==dis[i]&&temp<fa[i]) fa[i]=temp;
}
}
vis[temp]=false;
}
ans[0]=x;
temp=0;
while(fa[ans[temp]]!=inf)
{
ans[temp+1]=fa[ans[temp]];
temp++;
}
printf("From %d to %d :\nPath: ",x,y);
for(int i=0;i<temp;i++)
printf("%d-->",ans[i]);
printf("%d\n",ans[temp]);
printf("Total cost : %d\n\n",dis[x]-tax[x]);
}
int main()
{
while(~scanf("%d",&n)&&n)
{
for(int i=1;i<=n;i++)
for(int j=1;j<=n;j++)
scanf("%d",&a[i][j]);
for(int i=1;i<=n;i++)
scanf("%d",&tax[i]);
while(~scanf("%d%d",&x,&y)&&x!=-1)
{
if(x!=y) spfa();
else
{
printf("From %d to %d :\n",x,y);
printf("Path: %d\n",x);
printf("Total cost : 0\n\n");
}
}
}
return 0;
}