Cod sursa(job #2207433)

Utilizator cristianritaCristian Rita cristianrita Data 25 mai 2018 18:05:15
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.86 kb
#include <fstream>
#include <vector>
#include <queue>
#define maxn 100010
#define inf 1<<30
using namespace std;

ifstream in("bfs.in");
ofstream out("bfs.out");

int n,m,s;
queue<int> q;
vector<int> a[maxn];
vector<int> d(maxn, inf);

void bfs(int s) {
    d[s] = 0;
    q.push(s);
    int node;

    while(!q.empty()) {
        node = q.front();
        q.pop();
        for(int i = 0; i < a[node].size();i++) {
            int currentNode = a[node][i];
            if(d[currentNode] > d[node] + 1) {
                d[currentNode] = d[node] + 1;
                q.push(currentNode);
            }
        }
    }
}
int main() {
    in>>n>>m>>s;
    int x,y;
    for(int i = 0;i < m; i++) {
        in>>x>>y;
        a[x].push_back(y);
    }
    bfs(s);
    for(int i = 1; i <= n;i++)
        if(d[i] == inf)
            out<<"-1 ";
        else
            out<<d[i]<<" ";
}