hdu 1878

http://acm.hdu.edu.cn/showproblem.php?pid=1878

题意：就是判断这个图是不是一个欧拉回路的一个题，

思路：我觉得这个题可以用并查集判环加上判断每个点的度就行了

 1 #include <stdio.h>
 2 #include <string.h>
 3 #include <queue>
 4 using namespace std;
 5 int graph[1005];
 6 int belg[1005];
 7 
 8 
 9 int Find(int x)
10 {
11     int _x=x,_b;
12     while( _x != belg[ _x ] )
13         _x = belg[ _x ];
14     while( x != belg[ x ] )
15     {
16         _b = belg[ x ];
17         belg[ x ] = _x;
18         x = _b;
19     }
20     return _x;
21 }
22 
23 void unio(int x,int y)
24 {
25     int root1 = Find(x);
26     int root2 = Find(y);
27     if( root1 != root2 ) belg[root2] = root1;
28 }
29 
30 int main()
31 {
32     int n,m,a,b;
33     while(scanf("%d",&n)&&n)
34     {
35         int falg = 1,mark;
36         scanf("%d",&m);
37         memset(graph,false,sizeof(graph));
38         for(int i = 1 ; i <= n ; i++)
39             belg[i] = i;
40         for(int i = 1 ; i <= m ; i++ )
41         {
42             scanf("%d%d",&a,&b);
43             unio(a,b);
44             graph[a]++;
45             graph[b]++;
46         }
47         mark  = belg[1];
48         for(int i = 1 ; i <= n ; i++)
49         {
50             if(belg[i]!=mark||(graph[i]&1)) {
51                 falg = 0;
52                 break;
53             }
54         }
55         if(falg) printf("1
");
56         else printf("0
");
57     }
58 }