Cod sursa(job #2208354)

Utilizator SchnitzelMannPavaloiu Gabriel SchnitzelMann Data 29 mai 2018 12:37:00
Problema Sortare topologica Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.65 kb
#include <bits/stdc++.h>
#define N 50001
#define M 100001
using namespace std;
ifstream in("sortaret.in");
ofstream out("sortaret.out");
int nr,vf[2*M],urm[2*M],lst[N],arr[N],v[N],r;
void bfs(int x)
{
	int p=lst[x],y;
	while(p)
	{
		y=vf[p];
		arr[y]--;
		if(!arr[y])
		    v[r++]=y;
		p=urm[p];
	}
}
void ad(int x,int y)
{
	vf[++nr]=y;
	urm[nr]=lst[x];
	lst[x]=nr;
}
int main()
{
    int n,m,i,x,y,l=0;
    in>>n>>m;
	for(i=0;i<m;i++)
	{
		in>>x>>y;
		ad(x,y);
		arr[y]++;
	}
	for(i=1;i<=n;i++)
	    if(arr[i]==0)
	        v[r++]=i;
	while(l<r)
	    bfs(v[l++]);
	for(i=0;i<r;i++)
	    out<<v[i]<<" ";
    return 0;
}