Cod sursa(job #1822453)

Utilizator MithrilBratu Andrei Mithril Data 4 decembrie 2016 22:12:47
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.94 kb
#include <bits/stdc++.h>
using namespace std;

ifstream fin("bfs.in");
ofstream fout("bfs.out");
int n,m,x,y,s,top;
vector<int> adj[100001];
vector<int> dist;
vector<int> parent;
vector<char> color;
queue<int> Q;

int main()
{
    fin>>n>>m>>s;
    color.resize(n+1,'w');
    dist.resize(n+1,INT_MAX);
    parent.resize(n+1,-1);
    for(int i=1;i<=m;i+=1)
    {
        fin>>x>>y;
        adj[x].push_back(y);
    }
    Q.push(s);
    dist[s]=0;
    while(!Q.empty())
    {
        top=Q.front();
        for(auto i:adj[top])if(color[i]=='w')
        {
            color[i]='g';
            dist[i]=min(dist[top]+1,dist[i]);
            parent[i]=top;
            Q.push(i);
        }
        Q.pop();
        color[top]='b';
    }
    for(int i=1;i<=n;i+=1)
    {
        if(dist[i]!=INT_MAX)
            fout<<dist[i]<<' ';
        else
            fout<<-1<<' ';
    }
    fin.close();fout.close();
    return 0;
}