hdu 3631 Shortest Path(Floyd)
#include<stdio.h>
#include<algorithm>
#include<string.h>
const int N=305;
using namespace std;
int main()
{
int cas=0,n,m,q,i,j,k,x,y,t,g[305][305],vis[305],inf=1<<30;
while(~scanf("%d%d%d",&n,&m,&q))
{
if(n==0) break;
if(cas) printf("\n");
memset(vis,0,sizeof(vis));
for(i=0; i<N; i++)
for(j=0; j<N; j++)
if(i==j) g[i][j]=0;
else g[i][j]=inf;
for(i=0;i<m;i++)
{
scanf("%d%d%d",&x,&y,&t);
if(g[x][y]>t) g[x][y]=t;
}
printf("Case %d:\n",++cas);
for(k=0;k<q;k++)
{
scanf("%d",&t);
if(t)
{
scanf("%d%d",&x,&y);
if(vis[x]==0||vis[y]==0) printf("ERROR! At path %d to %d\n",x,y);
else if(g[x][y]>=inf) printf("No such path\n");
else printf("%d\n",g[x][y]);
}
else
{
scanf("%d",&x);
if(vis[x])
{
printf("ERROR! At point %d\n",x);
}
else
{
vis[x]=1;
for(i=0;i<N;i++)
for(j=0;j<N;j++)
{
if(g[i][x]>=inf||g[x][j]>=inf) continue;
g[i][j]=min(g[i][j],g[i][x]+g[x][j]);
}
}
}
}
}
return 0;
}
错误代码
/* ***********************************************
Author :xryz
Email :523689985@qq.com
Created Time :6-10 22:57:56
File Name :a.cpp
************************************************ */
#include <stdio.h>
#include <string.h>
#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <string>
#include <math.h>
#include <stdlib.h>
#include <time.h>
using namespace std;
const int N=300+5;
const int inf=1<<20;
int edge[N][N],vis[N],use[N],n,m,q,dist[N];
int Dijkstra(int v0)
{
int i,j,k,minx,u;
memset(vis,0,sizeof(vis));
for(i=0; i<n; i++)
{
if(use[i]&&edge[v0][i]<inf) dist[i]=edge[v0][i];
else dist[i]=inf;
}
dist[v0]=0;
vis[v0]=1;
for(i=0; i<n-1; i++)
{
minx=inf,u=v0;
for(j=0;j<n;j++)
{
if(!vis[j]&&dist[j]<minx&&use[i])
{
minx=dist[j];
u=j;
}
}
vis[u]=1;
for(k=0;k<n;k++)
{
if(!vis[k]&&edge[u][k]<inf&&dist[k]>dist[u]+edge[u][k]&&use[k])
dist[k]=dist[u]+edge[u][k];
}
}
}
int main()
{
int x,y,c,i,j,cas=0;
//freopen("in.txt","r",stdin);
while(~scanf("%d%d%d",&n,&m,&q)&&n&&m&&q)
{
memset(use,0,sizeof(use));
memset(edge,0,sizeof(edge));
for(i=0; i<m; i++)
{
scanf("%d%d%d",&x,&y,&c);
if(edge[x][y]==0||edge[x][y]>c)
edge[x][y]=c;
}
for(i=0; i<n; i++)
for(j=0; j<n; j++)
{
if(i==j) edge[i][j]=0;
else if(edge[i][j]==0) edge[i][j]=inf;
}
if(cas) printf("\n");
printf("Case %d:\n",cas++);
for(int k=0; k<q; k++)
{
scanf("%d",&c);
if(c==0)
{
scanf("%d",&x);
if(use[x]==1) printf("ERROR! At point %d\n",x);
else use[x]=1;
}
else
{
scanf("%d%d",&x,&y);
if(use[x]==0||use[y]==0)
printf("ERROR! At path %d to %d\n",x,y);
else
{
if(x==y) printf("0\n");
else
{
Dijkstra(x);
if(dist[y]<inf) printf("%d\n",dist[y]);
else printf("No such path\n");
}
}
}
}
}
return 0;
}
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