小希的迷宫 

 1 #include <iostream>
 2 using namespace std;
 3 
 4 int p[100010];
 5 bool v[100010];
 6 
 7 void make_set()
 8 {
 9     for(int i = 0; i < 100010; ++i)
10     {
11         p[i] = i;
12         v[i] = false;
13     }
14 }
15 
16 int find_set(int x)
17 {
18     if(p[x] != x)
19         p[x] = find_set(p[x]);
20     return p[x];
21 }
22 
23 void union_set(int x, int y)
24 {
25     x = find_set(x);
26     y = find_set(y);
27     if(x != y)
28         p[y] = x;
29 }
30 
31 int main()
32 {
33     int a, b, x, y, count = 0, k = 0;
34     bool flag = true;
35     make_set();
36     while(scanf("%d%d", &a, &b) && (a != -1 || b != -1))
37     {
38         if(a == 0 && b == 0)
39         {
40             for(int i = 1; i < 100010; ++i)
41                 if(v[i] && p[i] == i)
42                     count++;
43             if(count == 1 && flag || k == 0)
44                 cout << "Yes" << endl;
45             else 
46                 cout << "No" << endl;
47             make_set();
48             flag = true;
49             count = 0;
50             k = 0;
51         }
52         else// if(flag)
53         {
54             k++;
55             v[a] = v[b] = true;
56             x = find_set(a);
57             y = find_set(b);
58             if(x == y)
59                 flag = false;
60             else// if(y == b)
61             {
62                 union_set(x, y);
63             }
64             /*
65             else if(a == x)
66             {
67                 union_set(b, a);
68             }
69             else
70             {
71                 union_set(x, y);
72             }
73             */
74         }
75     }
76     return 0;
77 }
78 
79 /*
80 6 8  5 3  5 2  6 4
81 5 6  0 0
82 
83 8 1  7 3  6 2  8 9  7 5
84 7 4  7 8  7 6  0 0
85 
86 3 8  6 8  6 4
87 5 3  5 6  5 2  0 0
88 
89 */

　　

并查集，模仿之后找到点感觉了
posted @ 2011-07-16 21:04  georgechen_ena  阅读(80)  评论(0)    收藏  举报