UVa 11987,Almost Union-Find,并查集

I hope you know the beautiful Union-Find structure. In this problem, you're to implement something similar, but not identical.

The data structure you need to write is also a collection of disjoint sets, supporting 3 operations:

1 p q

Union the sets containing p and q. If p and q are already in the same set, ignore this command.

2 p q

Move p to the set containing q. If p and q are already in the same set, ignore this command

3 p

Return the number of elements and the sum of elements in the set containing p.

Initially, the collection contains n sets: {1}, {2}, {3}, ..., {n}.

Input

There are several test cases. Each test case begins with a line containing two integers n and m (1<=n,m<=100,000), the number of integers, and the number of commands. Each of the next m lines contains a command. For every operation, 1<=p,q<=n. The input is terminated by end-of-file (EOF). The size of input file does not exceed 5MB.

Output

For each type-3 command, output 2 integers: the number of elements and the sum of elements.

Sample Input

5 71 1 22 3 41 3 53 42 4 13 43 3

Output for the Sample Input

3 123 72 8

题意：可删点的并查集。

      1 p q 合并元素P和Q所在的集合，如果二者已经在同一个集合中，忽略此命令

      2 p q 把元素P移动到Q所在的集合。如果二者已经在同一个集合中，忽略此命令

      3 p   输出p所在集合的元素个数

思路：点不要真删，只是将那个点的祖先的size-1，sum-这个点。然后开个新点。用个数组pos[]表示这个点现在的位置。

#include <iostream>#include <cstdio>#include <cstring>using namespace std;#define maxn 200080#define LL long long intint pos[maxn],father[maxn],rank1[maxn];LL sum[maxn];int cnt;int find(int x){if(x == father[x])return x;return father[x] = find(father[x]);}void init(int n){for(int i = 1;i <= n;i++){father[i] = i;rank1[i] = 1;pos[i] = i;sum[i] = i;}}void Union(int a,int b){int fa = find(a),fb = find(b);if(fa == fb)return;father[fa] = fb;rank1[fb] += rank1[fa];sum[fb] += sum[fa];}void Delete(int x){int xx = pos[x];int fx = find(xx);rank1[fx]--;sum[fx] -= x;pos[x] = ++cnt;father[cnt] = cnt;rank1[cnt] = 1;sum[cnt] = x;}void Update_Union(int a,int b){int posa = pos[a],posb = pos[b];Union(posa,posb);}void Update_Move(int a,int b){int posa = pos[a],posb = pos[b];if(find(posa) == find(posb))return;Delete(a);Union(pos[a],posb);}int query(int x){int posx = pos[x];int fx = find(posx);return fx;}int main(){//freopen("in.txt","r",stdin);int n,m,ope,p,q;while(scanf("%d%d",&n,&m)==2){init(n);cnt = n;while(m--){scanf("%d",&ope);switch(ope){case(1):{scanf("%d%d",&p,&q);Update_Union(p,q);break;}case(2):{scanf("%d%d",&p,&q);Update_Move(p,q);break;}case(3):{scanf("%d",&p);int pos = query(p);printf("%d %lld\n",rank1[pos],sum[pos]);break;}}}}return 0;}