二分图判定+点染色 BestCoder Round #48 ($) 1002 wyh2000 and pupil

 1 /*
 2     二分图判定+点染色：因为有很多联通块，要对所有点二分图匹配，若不能，存在点是无法分配的，no
 3             每一次二分图匹配时，将点多的集合加大最后第一个集合去
 4     注意：n <= 1，no，两个集合都至少有一人；ans == n，扔一个给另一个集合
 5 */
 6 #include <cstdio>
 7 #include <algorithm>
 8 #include <cstring>
 9 #include <cmath>
10 #include <string>
11 #include <vector>
12 #include <map>
13 using namespace std;
14 
15 const int MAXN = 1e5 + 10;
16 const int INF = 0x3f3f3f3f;
17 vector<int> G[MAXN];
18 int col[MAXN];
19 int cnt[3];
20 int n, m;
21 
22 bool DFS(int u)
23 {
24     for (int i=0; i<G[u].size (); ++i)
25     {
26         int v = G[u][i];
27         if (col[v] == -1) {
28             col[v] = 3 - col[u];    cnt[col[v]]++;
29             if (!DFS (v))   return false;
30         }
31         else if (col[v] == col[u])  return false;
32     }
33 
34     return true;
35 }
36 
37 void work(void)
38 {
39     memset (col, -1, sizeof (col));
40     int ans = 0;
41     for (int i=1; i<=n; ++i)
42     {
43         if (col[i] == -1)
44         {
45             col[i] = 1; cnt[1] = 1; cnt[2] = 0;
46             if (!DFS (i)) {
47                 puts ("Poor wyh");  return ;
48             }
49             ans += max (cnt[1], cnt[2]);
50         }
51     }
52     if (ans == n)   ans--;
53     printf ("%d %d\n", ans, n - ans);
54 }
55 
56 int main(void)      //BestCoder Round #48 ($) 1002    wyh2000 and pupil
57 {
58     int t;   scanf ("%d", &t);
59     while (t--)
60     {
61         scanf ("%d%d", &n, &m);
62         if (n <= 1) {
63             puts ("Poor wyh");  continue;
64         }
65         for (int i=1; i<=n; ++i)    G[i].clear ();
66         for (int i=1; i<=m; ++i)
67         {
68             int u, v;   scanf ("%d%d", &u, &v);
69             G[u].push_back (v); G[v].push_back (u);
70         }
71         work ();
72     }
73     
74 
75     return 0;
76 }