HDU2112 HDU Today 单源最短路

单源最短路，Dijkstra算法

只需把每一个字符串地址对应一个数字即可，可以用map来实现

#include <cstdio>
#include <map>
#include <string>
#include <algorithm>
#include <cstring>
#include <iostream>
#define INF 999999999
#define MAX 200
using namespace std; int s[MAX],n[MAX]; int dist[MAX],ans[MAX][MAX]; void Dijkstra(int n,int v) { int newdist,temp,u,i,j; for(i=v;i<=n;i++) {
        dist[i]=ans[v][i];
        s[i]=0; }
    dist[v]=0;
    s[v]=1; for(i=v;i<=n;i++) {
        temp=INF;
        u=v; for(j=v;j<=n;j++) if((!s[j])&&(dist[j]<temp)) {
              u=j;
              temp=dist[j]; }
        s[u]=1; for(j=v;j<=n;j++) if((!s[j])&&(ans[u][j]<INF)) {
              newdist=dist[u]+ans[u][j]; if(newdist<dist[j])  dist[j]=newdist; } } } int main() { char start[35],end[35]; char a[35],b[35]; int N,t,i,k; bool flag;
    map<string,int> station; while(scanf("%d",&N)!=-1&&N!=-1) {
        station.clear();
        flag=false; for(int i=0;i<160;i++) for(int j=0;j<=160;j++)
            ans[i][j]=INF;
        scanf("%s%s",start,end);
        station[start]=1;
        station[end]=2;
        k=3; if(strcmp(start,end)==0)  flag=true; for(i=0;i<N;i++) {
            scanf("%s%s%d",a,b,&t); if(!station[a])  station[a]=k++; if(!station[b])  station[b]=k++;
            ans[station[a]][station[b]]=ans[station[b]][station[a]]=t; } if(flag)  puts("0"); else {
            k--;
            Dijkstra(k,1); if(dist[2]==INF)  puts("-1"); else printf("%d\n",dist[2]); } } return 0; }