PATA1107题解

并查集

//
//  main.cpp
//  PATA1107
//
//  Created by Phoenix on 2018/2/23.
//  Copyright © 2018年 Phoenix. All rights reserved.
//

#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;
const int maxn = 1010;
int father[maxn];
bool flag[maxn] = {false};
int num[maxn] = {0};
int findFather(int x) {
    int a = x;
    while(a != father[a]) {
        a = father[a];
    }
    while (x != father[x]) {
        int c = father[x];
        father[x] = a;
        x = c;
    }
    return a;
}

void Union(int a, int b) {
    int faA = findFather(a);
    int faB = findFather(b);
    if(faA != faB) father[faB] = faA;
}

bool cmp(int a, int b) {
    return a > b;
}

int main(int argc, const char * argv[]) {
    for(int i = 0; i < maxn; i++) {
        father[i] = i;
    }
    int n;
    scanf("%d", &n);
    for(int i = 0; i < n; i++) {
        int k, a;
        scanf("%d: %d", &k, &a);
        flag[a] = true;
        num[a]++;
        for(int j = 1; j < k; j++) {
            int b;
            scanf("%d", &b);
            flag[b] = true;
            Union(a, b);
        }
    }
    int k = 0;
    for(int i = 0; i < maxn; i++) {
        if(father[i] == i && flag[i] == true) k++;
    }
    printf("%d\n", k);
    for(int i = 0; i < maxn; i++) {
        if(num[i] && findFather(i) != i) {
            num[findFather(i)] += num[i];
            num[i] = 0;
        }
    }
    sort(num, num + maxn, cmp);
    for(int i = 0; i < k; i++) {
        printf("%d", num[i]);
        if(i < k - 1) printf(" ");
        else printf("\n");
    }
    return 0;
}