백준 11724번 C++

#include <iostream>

#include <vector>

#include <cstring>

#include <algorithm>

using namespace std;

int n, m;

vector<pair<int, int>> way;

int visited[1000];

void dfs(int i) {

visited[i] = 1;

for (int k = 0; k < way.size(); k++) {

if (way[k].first == i) {

if (visited[way[k].second] == 0)

dfs(way[k].second);

}

}

}

int main(void) {

cin >> n >> m;

memset(visited, 0, sizeof(visited));

for (int i = 0; i < m; i++) {

int x, y;

cin >> x >> y;

way.push_back(make_pair(x, y));

way.push_back(make_pair(y, x));

}

int answer = 0;

for (int i = 1; i <= n; i++) {

if (visited[i]== 0) {

dfs(i);

answer += 1;

}

}

cout << answer;

}