leetcode 547. 省份数量

c++

class Solution {
public:
    class UnionSet {
    public:
        int *father, n;
        UnionSet(int n) : n(n) {
            father = new int[n + 1]; 
            for (int i = 0; i <= n; i++) {
                father[i] = i;
            }
        }
        int find(int x) {
            return father[x] = (father[x] == x ? x : find(father[x]));
        }
        void merge(int a, int b) {
            father[find(a)] = find(b);
            return ;
        }
    };
    int findCircleNum(vector<vector<int>>& isConnected) {
        UnionSet u(isConnected.size());
        for (int i = 0; i < isConnected.size(); i++) {
            for (int j = 0; j < isConnected[0].size(); j++) {
                if (isConnected[i][j] == 1) {
                    u.merge(i, j);
                }
            }
        }
        int ans = 0;
        for (int i = 0; i < isConnected.size(); i++) {
            if (u.father[i] == i) ans++; 
        }
        return ans;
    }
};

js

class UnionSet {
    constructor(n) {
        this.father = new Array(n);
        for (var i = 0; i < n; i++) this.father[i] = i;
    }
    find(x) {
        return this.father[x] = (this.father[x] == x ? x : this.find(this.father[x]));
    }
    merge(a, b) {
        this.father[this.find(a)] = this.find(b); 
    } 
};
var findCircleNum = function(isConnected) {
    var u = new UnionSet(isConnected.length);
    for (var i = 0; i < isConnected.length; i++) {
        for (var j = 0; j < isConnected[0].length; j++) {
            if (isConnected[i][j] == 1) u.merge(i, j);
        }
    }
    var ans = 0;
    for (var i = 0; i < u.father.length; i++) {
        if (i == u.father[i]) ans++;
    }
    return ans;
};