hd 2112 HDU Today

  1 #include <stdio.h>
  2 #include <string.h>
  3 #include <queue>
  4 #define inf 0x3f3f3f3f
  5 #define N 1000000
  6 using namespace std;
  7 int vis[200], dis[200], head[200];
  8 int n, cnt, k;
  9 char s1[40], s2[40];
 10 char sta[200][40];
 11 struct note
 12 {
 13     int from, to, cost, next;
 14 }edge[N];
 15 void add(int x, int y, int z)
 16 {
 17     note e = {x, y, z, head[x]};
 18     edge[cnt] = e;
 19     head[x] = cnt++;
 20 }
 21 void spfa()
 22 {
 23     queue<int>q;
 24     memset(vis, 0, sizeof(vis));
 25     memset(dis, inf, sizeof(dis));
 26     q.push(1);
 27     vis[1] = 1;
 28     dis[1] = 0;
 29     while(!q.empty())
 30     {
 31         int u = q.front();
 32         q.pop();
 33         vis[u] = 0;
 34         for(int i = head[u]; i != -1; i = edge[i].next)
 35         {
 36             int v = edge[i].to;
 37             if(dis[v] > dis[u] + edge[i].cost)
 38             {
 39                 dis[v] = dis[u] + edge[i].cost;
 40                 if(!vis[v])
 41                 {
 42                     vis[v] = 1;
 43                     q.push(v);
 44                 }
 45             }
 46         }
 47     }
 48     if(dis[2] == inf)
 49         printf("-1\n");
 50     else
 51         printf("%d\n", dis[2]);
 52 }
 53 int main()
 54 {
 55     int a, b, c;
 56     while(~scanf("%d", &n), n != -1)
 57     {
 58         int flag;
 59         k = 2, cnt = 0;
 60         scanf("%s%s", sta[1], sta[2]);
 61         memset(head, -1, sizeof(head));
 62         for(int i = 0; i < n; i++)
 63         {
 64             scanf("%s%s%d", s1, s2, &c);
 65             flag = 1;
 66             for(int i = 1; i <= k; i++)
 67             {
 68                 if(strcmp(s1, sta[i]) == 0)
 69                 {
 70                     flag = 0;
 71                     a = i;
 72                     break;
 73                 }
 74             }
 75             if(flag)
 76             {
 77                 strcpy(sta[++k], s1);
 78                 a = k;
 79             }
 80             flag = 1;
 81             for(int i = 1; i <= k; i++)
 82             {
 83                 if(strcmp(sta[i], s2) == 0)
 84                 {
 85                     b = i;
 86                     flag = 0;
 87                     break;
 88                 }
 89             }
 90             if(flag)
 91             {
 92                 strcpy(sta[++k], s2);
 93                 b = k;
 94             }
 95             add(a, b, c);
 96             add(b, a, c);
 97         }
 98         if(strcmp(sta[1], sta[2]) == 0)
 99         {
100             printf("0\n");
101             continue;
102         }
103         spfa();
104     }
105     return 0;
106 }