Graph

bfs.cpp

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

using namespace std;

void bfs(vector<bool> &visited,vector<vector<int>> edge,vector<int> &distance, int node){
    queue<int> q;
    q.push(node);
    visited[0] = true;
    visited[node] = true;
    
    while(!q.empty()){
        node = q.front();
        q.pop();
        
        for(int i=0; i < edge.size(); i++){
            if(edge[i][0] == node && !visited[edge[i][1]]){
                int n =edge[i][1];
                distance[n] = distance[node] + 1;
                q.push(n);
                visited[n] = true;
            }
            else if(edge[i][1] == node && !visited[edge[i][0]]){
                int n =edge[i][0];
                distance[n] = distance[node] + 1;
                q.push(n);
                visited[n] = true;
            }
        }
    }  
}

int solution(int n, vector<vector<int>> edge) {
    int answer = 0;
    vector<bool> visited(n+1,false);
    vector<int> distance(n+1, 0);
    
    bfs(visited,edge,distance, 1);
    
    sort(distance.begin(), distance.end(), greater<int>());
    int max_dis = distance[0];
    for(int d : distance) if(d == max_dis) answer++;
    
    return answer;
}

dfs.cpp

#include <iostream>
#include <cstring>

using namespace std;

int graph[1001][1001];
int visited[1001];
int N,M,V;

void dfs(int v){
    cout<< v << " ";
    visited[v]=1;
    for(int i=1; i<=N ;i++){
        if(graph[v][i] && !visited[i])
            dfs(i);
    }

}

int main(){
    int a,b;

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

    cout <<"정점, 간선, 시작 정점 : ";
    cin >> N >> M >> V;
    for(int i=0; i<M; i++){
        cout << "연결된 두 정점 번호 : ";
        cin >>  a >> b;
        graph[a][b]=1;
        graph[b][a]=1;
    }
    dfs(V);
}