【HDOJ】1272 小希的迷宫

并查集。

 1 #include <stdio.h>
 2 #include <string.h>
 3 
 4 #define MAXNUM 100001
 5 
 6 int bin[MAXNUM];
 7 
 8 int find(int x) {
 9     int r = x;
10 
11     while (r != bin[r])
12         r = bin[r];
13 
14     return r;
15 }
16 
17 int merge(int x, int y) {
18     int fx, fy;
19 
20     fx = find(x);
21     fy = find(y);
22 
23     if (fx == fy)
24         return -1;
25     else
26         bin[fx] = fy;
27 
28     return 0;
29 }
30 
31 int main() {
32     int x, y;
33     int i, flg = 0, cnt, tmp;
34 
35     while (scanf("%d %d", &x, &y) != EOF) {
36         if (x==-1 && y==-1)
37             break;
38         if (x==0 && y==0) {
39             cnt = 0;
40             for (i=1; cnt<=1&&i<MAXNUM; ++i)
41                 if (bin[i] == i)
42                     ++cnt;
43             if (cnt>1 || flg)
44                 printf("No\n");
45             else
46                 printf("Yes\n");
47             flg = 0;
48             memset(bin, 0, sizeof(bin));
49         } else {
50             if ( bin[x] == 0 )
51                 bin[x] = x;
52             if ( bin[y] == 0)
53                 bin[y] = y;
54             tmp = merge(x, y);
55             if ( !flg ) flg = tmp;
56         }
57     }
58 
59     return 0;
60 }

 

posted on 2014-04-29 15:03  Bombe  阅读(185)  评论(0)  编辑  收藏  举报

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