HDU Today---hdu2112（最短路-_-坑在是无向图）

#include <iostream>
#include <cstdlib>
#include <cstdio>
#include <algorithm>
#include <vector>
#include <queue>
#include <cmath>
#include <stack>
#include <cstring>
#include <map>
#include <string>
using namespace std;
#define INF 0xfffffff
#define N 12000
#define met(a, b) memset(a, b, sizeof(a))
typedef long long LL;

struct node
{
int v, t;
node(int v, int t):v(v), t(t){}
};

vector<vector<node> >G;

int s, e;
int cnt, vis
, dist
;

int spfa()
{
met(vis, 0);
for(int i=1; i<cnt; i++)
dist[i] = INF;
queue<int>Q;
Q.push(s);
vis[s] = 1;
dist[s] = 0;

while(Q.size())
{
int p = Q.front(); Q.pop();
vis[p] = 0;
int len = G[p].size(), q;
for(int i=0; i<len; i++)
{
q = G[p][i].v;
if( dist[q] > dist[p]+G[p][i].t )
{
dist[q] = dist[p]+G[p][i].t;
if(vis[q] == 0)
{
vis[q] = 1;
Q.push(q);
}
}
}
}
return dist[e]==INF?-1:dist[e];
}
int main()
{
int n;
while(scanf("%d", &n), n!=-1)
{
map<string, int> M;
M.clear();
G.clear();
G.resize(n*2+5);

cnt = 1;

char s1[50], s2[50];

scanf("%s %s", s1, s2);

if( !M[s1] ) M[s1]  = cnt++;
if( !M[s2] ) M[s2]  = cnt++;

s = M[s1];
e = M[s2];

for(int i=1; i<=n; i++)
{
int t, u, v;
scanf("%s %s %d", s1, s2, &t);
if(!M[s1]) M[s1]  = cnt++;
if(!M[s2]) M[s2]  = cnt++;
u = M[s1];
v = M[s2];
G[u].push_back(node(v, t));
G[v].push_back(node(u, t));
}

printf("%d\n", spfa());
}
return 0;
}