Cod sursa(job #2550531)

Utilizator RobertuRobert Udrea Robertu Data 18 februarie 2020 20:48:13
Problema BFS - Parcurgere in latime Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.19 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <vector>
using namespace std;

ifstream f("bfs.in");
ofstream of("bfs.out");

vector< vector< int > > lista_adc;
queue< pair<int, int> > coada;
vector<int> d;
vector<bool> viz;
int n, cnt;

void bfs(int start) {
    viz[start] = 1;
    d[ start ] = cnt;
    cnt++;

    coada.push( make_pair( start, cnt ) );
    while( !coada.empty() ) {
        pair<int, int> nod = coada.front();
        viz[nod.first] = 1;
        coada.pop();

        for(int j = 0; j < lista_adc[ nod.first ].size(); j++)
           if( !viz[ lista_adc[nod.first][j] ] ) {
                coada.push( make_pair( lista_adc[nod.first][j], nod.second + 1 ) );
                d[ lista_adc[nod.first][j] ] = nod.second;
           }
        ///of << nod << " ";
    }
}

int main()
{
    int k, i, j, m, s;
    f >> n >> m >> s;

    d.assign( n + 1, -1 );
    lista_adc.assign( n + 1, vector<int>() );
    viz.assign( n + 1, 0 );

    for(k = 0; k < m; k++) {
        f >> i >> j;
        lista_adc[i].push_back( j );
    }

    cnt = 0;
    bfs( s );

    for(i = 1; i <= n; i++)
        of << d[i] << " ";

    return 0;
}