Cod sursa(job #1522793)

Utilizator mariakKapros Maria mariak Data 11 noiembrie 2015 23:07:24
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.07 kb
#include <cstdio>
#include <algorithm>
#include <vector>
#include <deque>
#include <cstring>
#define Nmax 100002

using namespace std;
int N, M, S, Cost[Nmax];
bool viz[Nmax];
deque <int> Q;
vector <int> v[Nmax];
void read()
{
    int x, y;
    freopen("bfs.in", "r", stdin);
    freopen("bfs.out", "w", stdout);
    scanf("%d %d %d", &N, &M, &S);
    for(int i = 1; i <= M; ++ i)
    {
        scanf("%d %d", &x, &y);
        v[x].push_back(y);
    }
}
void BFS()
{
    int x, i;
    viz[S] = 1;
    Q.push_back(S);
    memset(Cost, -1, sizeof(Cost));
    Cost[S] = 0;
    while(!Q.empty())
    {
        x = Q.front();
        Q.pop_front();
        for(i = 0; i < v[x].size(); ++ i)
        {
            if(!viz[v[x][i]])
            {
                Q.push_back(v[x][i]);
                Cost[v[x][i]] = Cost[x] + 1;
                viz[v[x][i]] = 1;
            }
        }
    }
}
void write()
{
    for(int i = 1; i <= N; ++ i)
        printf("%d ", Cost[i]);
}
int main()
{
    read();
    BFS();
    write();
    return 0;
}