UF.h (初始化,查找,合并接口）
1 void UFinit(int);
2 //int UFfind(int, int);
3 int UFunion(int, int);
4 int UFnum(int, int);
UF.c (接口实现)
1 #include<stdlib.h>
2 #include "UF.h"
3
4 typedef struct
5 {
6 int *id,*sz;
7 }id_sz;
8 static id_sz ID;
9 void UFinit(int N)
10 {
11 ID.id=malloc(N*sizeof(int));
12 ID.sz=malloc(N*sizeof(int));
13 for(int i=0; i<N; i++)
14 {
15 ID.id[i]=i;
16 ID.sz[i]=1;
17 }
18 }
19 static int find(int x)
20 {
21 while(x!=ID.id[x])
22 {
23 ID.id[x]=ID.id[ID.id[x]];
24 x=ID.id[x];
25 }
26 return x;
27 }
28
29 /*
30 int UFfind(int p, int q)
31 {
32 return (find(p)==find(q));
33 }
34
35 void UFunion(int p, int q)
36 {
37 int i=find(p),j=find(q);
38 if(i==j) return;
39 if(sz[i]<sz[j])
40 {
41 id[i]=j;
42 sz[j]+=sz[i];
43 }
44 else
45 {
46 id[j]=i;
47 sz[i]+=sz[j];
48 }
49 }*/
50 int UFunion(int p, int q)
51 {
52 int i=find(p),j=find(q);
53 if(i==j) return 0;
54 if(ID.sz[i]<ID.sz[j])
55 {
56 ID.id[i]=j;
57 ID.sz[j]+=ID.sz[i];
58 }
59 else
60 {
61 ID.id[j]=i;
62 ID.sz[i]+=ID.sz[j];
63 }
64 return 1;
65 }
66
67 int UFnum(int p, int N)
68 {
69 int k=N-1,i=k,num=0;
70
71 //while(p!=id[p])
72 //p=id[p];
73 p=find(p);
74 while(k>=0)
75 {
76 //while(i!=id[i])
77 //i=id[i];
78 i=find(i);
79 if(p==i)num++;
80 i=--k;
81 }
82 return num--;
83 }
main.c (主程序)
1 #include <stdio.h>
2 #include "UF.h"
3
4 int main(void)
5 {
6 int p,q,N;
7
8 scanf("%d",&N);
9 getchar();
10
11 UFinit(N);
12 /* while(scanf("%d %d", &p, &q)==2)
13 if(!UFfind(p, q))
14 {
15 UFunion(p, q);
16 printf("%d %d
",p, q);
17 }
18 */
19 while(scanf("%d %d", &p, &q)==2)
20 {
21 if(UFunion(p, q))
22 {
23 printf("%d %d
",p, q);
24 }
25 }
26 //printf("%d",UFnum(0, N));
27 return 0;
28 }