Directed Graph Connectivity

    1#include <bits/stdc++.h>
    2 
    3using namespace std;
    4 
    5void dfs(int n, int indx, pair<int, int> bad, vector<bool> &visited, vector<vector<int>> &adj){
    6    if(visited[indx]) return;
    7    visited[indx] = true;
    8    if(indx == n) return;
    9    for(int c : adj[indx]){
    10        if(!(indx == bad.first && c == bad.second)) dfs(n, c, bad, visited, adj);
    11    }
    12}
    13int main(){
    14    ios::sync_with_stdio(0);
    15    cin.tie(0);
    16    int n, m;
    17    cin >> n >> m;
    18    vector<vector<int>> adj(n + 1);
    19    unordered_map<int, pair<int, int>> day;
    20    for(int i = 0; i <m; i++){
    21        int x, y;
    22        cin >> x >> y;
    23        x--; y--;
    24        adj[x].push_back(y);
    25        day[i] = make_pair(x, y);
    26    }
    27    for(int i = 0; i < m; i++){
    28        pair bad = day[i];
    29        vector<bool> visited(n, false);
    30        dfs(n - 1, 0, bad, visited, adj);
    31        if(visited[n - 1]){
    32            cout << "YES\n";
    33        } else {
    34            cout << "NO\n";
    35        }
    36    }
    37    return 0;
    38}