Cod sursa(job #2348786)

Utilizator Horea_Mihai_SilaghiHorea Mihai Silaghi Horea_Mihai_Silaghi Data 19 februarie 2019 23:35:51
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.96 kb
#include <fstream>
#include<vector>
#define maxn 100010
using namespace std;

ifstream cin("bfs.in");
ofstream cout("bfs.out");
vector <int> a[maxn];

int cost[maxn],s[maxn],g[maxn],n,m,st,l;

void citire()
{
    int x,y;
    cin>>n>>m>>st;
    for(int i=1;i<=m;i++)
    {
        cin>>x>>y;
        a[x].push_back(y);
    }
    for(int i=1;i<=n;i++)
        g[i]=a[i].size();
}

void bfs(int nod)
{
    int i=1,j=1;
    l=1;
    cost[nod]=0;
    s[1]=nod;
    while(i<=l)
    {
        for(j=0;j<g[s[i]];j++)
        {
            if(cost[a[s[i]][j]]==0&&a[s[i]][j]!=nod)
            {
                l++;
                s[l]=a[s[i]][j];
                cost[a[s[i]][j]]=cost[s[i]]+1;
            }
        }
        i++;
    }
}
int main()
{
    citire();
    bfs(st);
    for(int i=1;i<=n;i++)
        if(cost[i]==0)
            cost[i]=-1;
    cost[st]=0;
    for(int i=1;i<=n;i++)
        cout<<cost[i]<<" ";
    return 0;
}