poj 2387 Til the Cows Come Home

/*
Name:poj 2387 Til the Cows Come Home
Author: Unimen
Date: 25/04/11 19:21
Description:单源最短路径Dijkistra, SPFA解法
*/
/*
解题报告：
1、注意有重边(即到某一点的权值有多种)， 在输入时处理掉
*/
//Dijkistra解法
#include <iostream>
using namespace std;
const int MAXN = 1200;
const int oo = 2100000000;
int t, n;
int g[MAXN][MAXN];
int dis[MAXN], visited[MAXN];
void Dijkistra()
{
int i, j;
for(i=1; i<=n; ++i)
{
dis[i] = g[1][i];
visited[i] = 0;
}
dis[1] = 0, visited[1] = 1;
for(i=1; i<n; ++i)
{
int nMin = oo;
int index = 0;
for(j=1; j<=n; ++j)
{
if(!visited[j] && dis[j]<nMin)
{
index = j;
nMin = dis[j];
}
}
visited[index] = 1;
for(j=1; j<=n; ++j)
{
if(!visited[j] && g[index][j]!=oo && dis[j]>dis[index]+g[index][j])
dis[j]=dis[index]+g[index][j];
}
}
}
int main()
{
int i, j;
while(cin>>t>>n)
{
for(i=1; i<=n; ++i)
for(j=1; j<=n; ++j)
g[i][j] = oo;
for(i=1; i<=t; ++i)
{
int a, b, w;
cin>>a>>b>>w;
if(w < g[a][b])
g[a][b] = g[b][a] = w;
}
Dijkistra();
cout<<dis
<<endl;
}
return 0;
}
//SPFAQ解法
#include <iostream>
#include <queue>
#include <cstring>
using namespace std;
const int MAXN = 1200;
const int oo = 21000000;
int t, n;
int g[MAXN][MAXN];
int dis[MAXN];
void spfa()
{
queue<int>	que;
que.push(1);
dis[1] = 0;
while(!que.empty())
{
int x = que.front();
que.pop();
for(int i=1; i<=n; i++)
{
if(g[x][i]!=oo && dis[i] > dis[x] + g[x][i])
{
dis[i] = dis[x] + g[x][i];
que.push(i);
}
}
}
}
int main()
{
int i, j;
while(cin>>t>>n)
{
for(i=1; i<=n; ++i)
{
for(j=1; j<=n; ++j)
{
g[i][j] = oo;
}
}

for(i=1; i<=t; ++i)
{
int a, b, w;
cin>>a>>b>>w;
if(g[a][b] > w)
g[a][b] = g[b][a] =w;
}
for(i=1; i<=n; ++i)
dis[i] = oo;
spfa();
cout<<dis
<<endl;
}
return 0;
}