[PS] 백준 1260번 - DFS와 BFS

DFS와 BFS의 구현을 요구하는 간단한 문제다.

#include <iostream>
#include <vector>
#include <queue>
#include <cstring>
#include <algorithm>

using namespace std;

int N, M, V;
vector<int> graph[1001];
bool visit[1001];

void BFS(int idx) {
    memset(visit, false, sizeof(visit));
    queue<int> q;
    q.push(idx);
    visit[idx]=true;

    while(!q.empty()){
        int now = q.front();
        q.pop();
        cout << now << " ";
        for(int i=0; i<graph[now].size(); i++){
            int next=graph[now][i];
            if(!visit[next]){
                q.push(next);
                visit[next]=true;
            }
        }
    }
}

void DFS(int idx) {
    visit[idx]=true;
    cout << idx << " ";
    for(int i=0; i<graph[idx].size(); i++){
        int next=graph[idx][i];
        if(!visit[next]) DFS(next);
    }
}

int main(void){
    cin >> N >> M >> V;
    for(int i=0; i<M; i++) {
        int x, y;
        cin >> x >> y;
        graph[x].push_back(y);
        graph[y].push_back(x);
    }
    for(int i=1; i<=N; i++) sort(graph[i].begin(), graph[i].end());
    DFS(V);
    cout << "\n";
    BFS(V);
}