dd第一课：并查集 

 1 #include <stdio.h>
 2 #include <string.h>
 3 #define MAX 1000
 4 
 5 int p[MAX];
 6 int rank[MAX];
 7 void init(int n){
 8     int i;
 9 //    memset(rank, 0, sizeof(rank));
10     for(i=1;i<n;i++) {p[i]=i;rank[i]=0;}
11 }
12 
13 
14 int find_root_digui(int x){
15     if(x!=p[x])
16         return p[x]=find_root(p[x]);
17     else return x;
18 } 
19 
20 int find_root(int x){
21     
22     int i=x;
23     while(i!=p[i])
24         i=p[i];
25     int rot=i;
26     int temp;
27     i=x;
28     while (i!=p[i]){
29         temp=i;
30         i=p[i];
31         p[temp]=rot;
32     }
33     return rot;
34 }
35 
36 int conn(int x,int y){
37     x=find_root(x);
38     y=find_root(y);
39     return x==y;
40 }
41 
42 void _union(int x,int y){
43     x=find_root(x);
44     y=find_root(y);
45 
46     if(rank[x]>=rank[y])
47         p[y]=x;
48     else p[x]=y;
49     
50     if(rank[x]==rank[y]) rank[x]++;
51 }
52     
53 void try() 
54 {
55     _union(1,2);
56     _union(3,4);
57     _union(2,4);
58     _union(5,6);
59     _union(7,8);
60     _union(6,8);
61     _union(2,6);
62     int root = find_root(8);
63     printf("root = %d\n", root);
64     
65     for(int i=1; i<10; i++)
66     {
67         printf("p[%d]=%d, rank[%d]=%d\n", i, p[i], i, rank[i]);
68     }
69     
70     while(1)
71     {
72         int a, b;
73         scanf("%d%d", &a, &b);
74         printf("%d\n", conn(a,b));
75         printf("%d\n",rank[1]);
76         printf("%d\n",find_root(1));
77     }
78     
79 }
80 
81 int main(){
82     int n=20;
83     init(n);
84     try();
85     return 0;
86 }

 

posted @ 2013-05-02 10:34  Levi.duan  阅读(202)  评论(0)    收藏  举报