hdu2112HDU Today

#include<iostream>#include<cstdio>#include<cstring>#include<string>#include<map>#include<algorithm>using namespace std;#define INF 0x3f3f3f3f#define Max 155int dis[Max], res[Max][Max];bool visit[Max];void Dijkstra(int start, int end){    int temp, k;    memset(visit, false, sizeof(visit));    for(int i = 1; i <= end; ++i)        dis[i] = res[start][i];    dis[start] = 0;    visit[start] = 1;    for(int i = 1; i <= end; ++i)    {        temp = INF;        for(int j = 1; j <= end; ++j)            if(!visit[j] && temp > dis[j])                temp = dis[k = j];        if(temp == INF) break;        visit[k] = 1;        for(int j = 1; j <= end; ++j)            if(!visit[j] && dis[j] > dis[k] + res[k][j])                dis[j] = dis[k] + res[k][j];    }}int main(){    int num, count;    char s[32], e[32];    bool flag;    char str[32], str1[32];    int cost;    map<string, int>car;    while(scanf("%d", &num) != EOF && num != -1)    {        flag = 0;        car.clear();        memset(res, INF, sizeof(res));        count = 3;        scanf("%s%s", s, e);        if(strcmp(s, e) == 0)            flag = 1;        car[s] = 1;        car[e] = 2;        for(int i = 1; i <= num; ++i)        {            scanf("%s%s%d", str, str1, &cost);            if(!car[str])                car[str] = count++;            if(!car[str1])                car[str1] = count++;            if(cost < res[car[str]][car[str1]])  //注意： 再输入两边和对应权值时， 一定要判断当前权值是否小于输入                                                     //权值，后选择是否更新， 不然WA；                res[car[str]][car[str1]] = res[car[str1]][car[str]] = cost;        }        if(flag)  //剪枝， 防止无谓的用时；        {            printf("0\n");            continue;        }        Dijkstra(1, count - 1);//此处应用 count -1； 为此错了好几次        if(dis[2] == INF)            printf("-1\n");        else            printf("%d\n", dis[2]);    }    return 0;}