Cod sursa(job #2113319)

Utilizator andysoloAndrei Solo andysolo Data 24 ianuarie 2018 14:51:15
Problema BFS - Parcurgere in latime Scor 40
Compilator cpp Status done
Runda Arhiva educationala Marime 1.08 kb
#include <iostream>
#include <cstdio>
#include <vector>
#include <queue>
#include <cstring>
#define NMAX 100000+5
using namespace std;

int N,M,S;
vector<int> leg[NMAX];
queue<int> q;
int v[NMAX];

int bfs(int nod)
{
    q.push(S);
    v[S]=1;
    while(!q.empty())
    {
        int p=q.front();
        for(int i=0;i<leg[p].size();i++)
        {
            int t=leg[p][i];
            if(t==nod){
                if(S==nod)
                return 0;
                else
                return v[p];
            }
            else if(v[t]==0)
            {
                v[t]=v[p]+1;
                q.push(t);
            }
        }
    q.pop();
    }
    return -1;
}

int main()
{
    freopen("bfs.in","r",stdin);
    freopen("bfs.out","w",stdout);

    scanf("%d %d %d",&N,&M,&S);
    for(int i=1;i<=M;i++)
    {
        int x,y;
        scanf("%d %d",&x,&y);
        leg[x].push_back(y);
    }

    for(int i=1;i<=N;i++){
    printf("%d ",bfs(i));
    memset(v,0,100005);
    while(!q.empty())
        q.pop();
    }

    return 0;
}