Cod sursa(job #2854622)

Utilizator iraresmihaiiordache rares mihai iraresmihai Data 21 februarie 2022 15:40:21
Problema BFS - Parcurgere in latime Scor 50
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.03 kb
#include <iostream>
#include <vector>

#define MAXN 100000

using namespace std;

struct node{
  vector <int> edges;
  int dist;
};

node graph[MAXN + 1];
int s;

static inline void addEdge(int a, int b) {
  graph[a].edges.push_back(b);
}

void bfs(int pos, int dist) {
  int i;

  graph[pos].dist = dist;

  for ( i = 0; i < graph[pos].edges.size(); i++ ) {
    if ( (graph[graph[pos].edges[i]].dist == 0 || graph[graph[pos].edges[i]].dist > dist) && graph[pos].edges[i] != s ) {
      bfs(graph[pos].edges[i], dist + 1);
    }
  }
}

int main() {
  FILE *fin, *fout;
  fin = fopen("bfs.in", "r");
  fout = fopen("bfs.out", "w");

  int n, m, a, b, i;

  fscanf(fin, "%d%d%d", &n, &m, &s);

  for ( i = 0; i < m; i++ ) {
    fscanf(fin, "%d%d", &a, &b);
    addEdge(a, b);
  }

  bfs(s, 0);

  for ( i = 1; i <= n; i++ ) {
    if ( graph[i].dist > 0 || i == s )
      fprintf(fout, "%d ", graph[i].dist);
    else
      fprintf(fout, "-1 ");
  }

  fclose(fin);
  fclose(fout);
  return 0;
}