프로그래머스 - 네트워크 (bfs, dfs or union-find)

#include <string>
#include <vector>
#include <algorithm>

using namespace std;

vector<int> parent;

int find(int n)
{
    if( n == parent[n]) return n;
    else return parent[n] = find(parent[n]);
}

void merge(int n, int v)
{
    n = find(n);
    v = find(v);
    if(n < v)
        parent[v] = find(n);
    else if (n > v)
        parent[n] = find(v);
}

int solution(int n, vector<vector<int>> computers) {
    int answer = 0;
    
    vector<int> p;
    
    for(int i = 0; i<n; ++i)
    {
        p.push_back(i);
    }
    parent = p;
    
    for(int i = 0; i < computers.size(); ++i)
    {
        for(int j = 0; j < computers[i].size(); ++j)
        {
            if(i == j) continue;
            if(computers[i][j] ==1)
            {
                int n = find(i);
                int v = find(j);
                if(n != v)
                {
                    merge(i,j);
                }
            }
        }
    }
    
    for(int i = 0 ; i<n; ++i)
        find(i);
    
    sort(parent.begin(), parent.end());
    
    auto End = unique(parent.begin(), parent.end());
    
    parent.erase(End, parent.end());
    
    answer = parent.size();
    
    return answer;
}