Cod sursa(job #2418236)

Utilizator AndrulianDin Iulian Andrulian Data 4 mai 2019 13:53:33
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.26 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <bitset>
#include <queue>
using namespace std;
//ifstream fin("bfs.in");
//ofstream fout("bfs.out");
FILE *fin=fopen("bfs.in","r");
FILE *fout=fopen("bfs.out","w");
const int nmax=100005;
char buff[nmax];
vector <int> g[nmax];
vector <int> viz(nmax,-1);
int n,m,s,poz;
__attribute__((always_inline))void read(int &nr)
{
    while(buff[poz]<'0' || buff[poz]>'9')
        if(++poz==nmax)
            fread(buff,1,nmax,fin),poz=0;
    while(buff[poz]>='0' && buff[poz]<='9')
    {
        nr=nr*10+buff[poz]-'0';
        if(++poz==nmax)
            fread(buff,1,nmax,fin),poz=0;
    }
}
void BFS(int s)
{
    queue <int> q;
    q.push(s);
    viz[s]=0;
    while(!q.empty())
    {
        int v=q.front();
        for(unsigned int i=0; i<g[v].size(); i++)
            if(viz[g[v][i]]==-1)
            {
                viz[g[v][i]]=viz[v]+1;
                q.push(g[v][i]);
            }
        q.pop();
    }

}
int main()
{
    read(n);
    read(m);
    read(s);
    for(int i=1; i<=m; i++)
    {
        int x=0,y=0;
        read(x);
        read(y);
        g[x].push_back(y);
    }
    BFS(s);
    for(int i=0; i<n; i++)
        fprintf(fout,"%d ",viz[i+1]);
}