Cod sursa(job #2672007)

Utilizator rares8wAncuta Rares rares8w Data 12 noiembrie 2020 22:10:08
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.83 kb
#include <bits/stdc++.h>
using namespace std;
ifstream f("bfs.in");
ofstream g("bfs.out");
vector<int>a[100005];
int n,m,nod,x,y;
int b[100005];
bool viz[100005];
void bfs(int v)
{
    queue <int> q;
    q.push(v);
    viz[v]=1;
    while(q.empty()==0)
    {
        int top=q.front();
        q.pop();
        for(int i=0; i<a[top].size(); i++)
            if(viz[a[top][i]]==0)
            {
                viz[a[top][i]]=1;
                q.push(a[top][i]);
                b[a[top][i]]=b[top]+1;
            }
    }
}
int main()
{
    f>>n>>m>>nod;
    for(int i=1; i<=m; i++)
    {
        f>>x>>y;
        a[x].push_back(y);
    }
    bfs(nod);
    for(int i=1; i<=n; i++)
        if(b[i])
            g<<b[i]<<" ";
        else if(i==nod)
            g<<0<<" ";
        else g<<-1<<" ";
    return 0;
}