HDU 2680Choose the best route （SPFA）

5 8 5
1 2 2
1 5 3
1 3 4
2 4 7
2 5 6
2 3 5
3 5 1
4 5 1
2
2 3
4 3 4
1 2 3
1 3 4
2 3 2
1
1

1
-1

#include <cstdio>
#include <cmath>
#include <cstring>
#include <cstdlib>
#include <climits>
#include <malloc.h>
#include <ctype.h>
#include <queue>
#include <stack>
#include <vector>
#include <deque>
#include <set>
#include <map>
#include <iostream>
#include <algorithm>
using namespace std;
#define pi acos(-1.0)
#define INF 0xffffff
#define N 1047
#define M 20047
int n,m,s,pp,ww,k,Edgehead[M],dis[M];
struct
{
	int v,w,next;
}Edge[2*M];
bool vis[M];
void Addedge(int u,int v,int w)
{
	Edge[k].next = Edgehead[u];
	Edge[k].w = w;
	Edge[k].v = v;
	Edgehead[u] = k++;
}
void SPFA( int start)
{
	queue<int>Q;
	for(int i = 1 ; i <= N ; i++ )
		dis[i] = INF;
	dis[start] = 0;
	memset(vis,false,sizeof(vis));
	Q.push(start);
	while(!Q.empty())//直到队列为空
	{
		int u = Q.front();
		Q.pop();
		vis[u] = false;
		for(int i = Edgehead[u] ; i!=-1 ; i = Edge[i].next)//注意
		{
			int v = Edge[i].v;
			int w = Edge[i].w;
			if(dis[v] > dis[u] + w)
			{
				dis[v] = dis[u]+w;
				if( !vis[v] )//防止出现环，也就是进队列重复了  
				{
					Q.push(v);
					vis[v] = true;
				}
			}
		}
	}
}
int main()
{
	int u,v,w;
	while(~scanf("%d%d%d",&n,&m,&s))
	{
		k = 1;
		memset(Edgehead,-1,sizeof(Edgehead));
		for(int i = 1 ; i <= m ; i++ )
		{
			scanf("%d%d%d",&u,&v,&w);
		//	Addedge(u,v,w);
			Addedge(v,u,w);//因为是反向寻找的而且道路是单向的，所以此处也要方向
		}
		SPFA(s);
		scanf("%d",&pp);
		int min = INF; 
		for(i = 0 ; i < pp ;i++)
		{
			scanf("%d",&ww);
			if(min > dis[ww])
				min = dis[ww];
		}
		if(min == INF)
			min = -1;
		printf("%d\n",min);
	}
	return 0;
}

#include<stdio.h>
#define max 1001
#define INF 100000000

int N;
int v[max];
int dis[max];
int g[max][max];

void dijk()
{
	int i,j,mark,mindis;
	for(i=0;i<=N;i++)
	{
		v[i] = 0;
		dis[i] = INF;
	}
	dis[0] = 0;
	v[0]  = 1;
	for(i=0;i<=N;i++)
	{
		mindis = INF;
		mark = 0;
		for(j=0;j<=N;j++)
		if(!v[j] && dis[j] < mindis)
		{
			mindis = dis[j];
			mark = j;
		}
		v[mark] = j;
		for(j=0;j<=N;j++)
		if(!v[j] && dis[j] > dis[mark] + g[mark][j])
			dis[j] = dis[mark] + g[mark][j];
	}
}

int main()
{
	int W,M,Q,i,j,d,a,b;
	while(~scanf("%d%d%d",&N,&M,&Q))
	{
		for(i=0;i<max;i++)
		for(j=0;j<max;j++)
		{
			if(i==j)g[i][j] = 0;
			else
			g[i][j] = INF;
		}
		while(M--)
		{
			scanf("%d%d%d",&a,&b,&d);
			if(d < g[a][b])
			g[a][b] = d;
		}
		scanf("%d",&W);
		while(W--)
		{
			scanf("%d",&a);
			g[0][a] = 0;
		}
		dijk();
		if(dis[Q] == INF)
		printf("-1\n");
		else
		printf("%d\n",dis[Q]);
	}
}