Cod sursa(job #1429582)

Utilizator PlatonVPlaton Vlad PlatonV Data 6 mai 2015 18:23:55
Problema BFS - Parcurgere in latime Scor 70
Compilator cpp Status done
Runda Arhiva educationala Marime 1 kb
#include <stdio.h>
#include <vector>
#include <queue>

using namespace std;

FILE* f;
FILE* r;

int N, M, S;
vector<int> g[100000];
int dist[100000];

void read()
{
    f = fopen("bfs.in", "r");

    fscanf(f, "%d%d%d", &N, &M, &S);

    for (int i = 0; i < M; ++i)
    {
        int x, y;
        fscanf(f, "%d%d", &x, &y);        
        g[x].push_back(y);
    }
}

void bfs(int s)
{
    queue<int> q;
    q.push(s);
    dist[s] = 0;

    while (!q.empty())
    {
        int x = q.front();
        for (int i = 0; i < g[x].size(); ++i)
        {
            if (dist[g[x][i]] == -1)
            {
                dist[g[x][i]] = dist[x] + 1;
                q.push(g[x][i]);
            }
        }
        q.pop();
    }
}

int main()
{
    read();

    for (int i = 0; i< N+1 ; i++)
        dist[i] = -1;

    bfs(S);

    r = fopen("bfs.out", "w");

    for (int i = 1; i <= N; i++)
    {
        fprintf(r, "%d ", dist[i]);
    }

    return 0;
}