UVA - 11987 Almost Union-Find（带删除的并查集）

Almost Union-Find

Time Limit: 1000MS Memory Limit: Unknown 64bit IO Format: %lld & %llu

Submit Status

Description

Problem A

Almost Union-Find

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

Explanation

Initially: {1}, {2}, {3}, {4}, {5}

Collection after operation 1 1 2: {1,2}, {3}, {4}, {5}

Collection after operation 2 3 4: {1,2}, {3,4}, {5} (we omit the empty set that is produced when taking out 3 from {3})

Collection after operation 1 3 5: {1,2}, {3,4,5}

Collection after operation 2 4 1: {1,2,4}, {3,5}

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Rujia Liu's Present 3: A Data Structure Contest Celebrating the 100th Anniversary of Tsinghua University
Special Thanks: Yiming Li
Note: Please make sure to test your program with the gift I/O files before submitting!

 带删除的并查集，用id[i]=ii代表数字i当前的位置，每次删除把id[i]指向其他位置，原来的位置舍去。

#include<iostream>#include<cstring>#include<cstdio>using namespace std;const int MAXN = 2e5 + 5;int F[MAXN], cnt[MAXN], id[MAXN], sum[MAXN];int dex;int n, k;void init(){for (int i = 0; i <= n; i++){F[i] = id[i] = sum[i] = i;cnt[i] = 1;}dex = n;}int find(int t){if (F[t] == t) return t;return F[t] = find(F[t]);}void Union(int a, int b){int p = find(a);int q = find(b);if (p != q){F[p] = q;cnt[q] += cnt[p];sum[q] += sum[p];}}void move(int a){int p = find(id[a]);cnt[p]--;sum[p] -= a;id[a] = ++dex;F[dex] = dex;cnt[dex] = 1;sum[dex] = a;}int main(){while (scanf("%d%d", &n, &k) != EOF){init();int op,a,b;while (k--){cin >> op;if (op == 1){cin >> a >> b;Union(id[a], id[b]);}else if (op == 2){cin >> a >> b;int p = find(id[a]);int q = find(id[b]);if (p != q){move(a);Union(id[a], id[b]);}}else if (op == 3){cin >> a;int p = find(id[a]);cout << cnt[p] << " " << sum[p] << endl;}}}}