Cod sursa(job #1609192)

Utilizator clopotelNeamtu Sergiu clopotel Data 22 februarie 2016 17:37:30
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.93 kb
#include <iostream>
#include <cstdio>
#include <queue>
#include <vector>
using namespace std;
FILE* f=fopen("bfs.in","r");
FILE* g=fopen("bfs.out","w");
int n,m,s,x,y,viz[100001];
queue <int> q;
vector <int> v[100001];
vector <int> ::iterator it;
void bfs(int s)
{
    int k=0;
    for(it=v[s].begin();it!=v[s].end();++it)
        q.push((*it)),viz[(*it)]=1;
    while(!q.empty())
    {
        int r=q.front();
        for(it=v[r].begin();it!=v[r].end();++it)
            if(!viz[(*it)])
                q.push((*it)),viz[(*it)]=viz[r]+1;
        q.pop();
    }
}
int main()
{
    fscanf(f,"%d%d%d",&n,&m,&s);
    for(int i=0;i<m;i++)
    {
        fscanf(f,"%d%d",&x,&y);
        v[x].push_back(y);
    }
    bfs(s);
    for(int i=1;i<=n;i++)
        if(viz[i] and i!=s)
            fprintf(g,"%d ",viz[i]);
        else if(i==s)
            fprintf(g,"%d ",0);
        else fprintf(g,"%d ",-1);
    return 0;
}