Cod sursa(job #3249622)

Utilizator pascarualexPascaru Alexandru pascarualex Data 17 octombrie 2024 12:45:40
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.01 kb
#include<vector>
#include<fstream>
#include<queue>

using namespace std;

int n, m, s;
vector<vector<int>> adj(100005);
vector<int> ans(100005,-1);


int bfs(int s, vector<vector<int>> &adj) {
    vector<int> visited(100005, 0);

    ans[s] = 0;

    queue<pair<int,int>> q;
    q.push({s,1});
    visited[s] = true;

    while(!q.empty()) {
        auto [node,dist] = q.front();
        q.pop();
        for(auto neighbour : adj[node]) {
            if(!visited[neighbour]) {
                if(ans[neighbour] == -1) {
                    ans[neighbour] = dist;
                }
                q.push({neighbour,dist + 1});
                visited[neighbour] = true;
            }
        }
        dist ++;
    }
    return -1;
}

int main() {
    ifstream fin("bfs.in");
    ofstream fout("bfs.out");
    fin >> n >> m >> s;

    for(int i = 1 ; i<=m ; i++) {
        int x, y;
        fin >> x >> y;
        adj[x].push_back(y);
    }

    bfs(s, adj);

    for(int i = 1 ; i <= n ; i++) {
        fout << ans[i] << " ";
    }
}