Pagini recente » Cod sursa (job #1742043) | Cod sursa (job #855134) | Cod sursa (job #1011630) | Cod sursa (job #961672) | Cod sursa (job #1732990)
#include<iostream>
#include<fstream>
#include<vector>
#include<queue>
#include<map>
#define DX 250100
using namespace std;
fstream fin("stramosi.in",ios::in),fout("stramosi.out",ios::out);
int inainte[DX+5],stra[22][DX+5],put[22],mp[DX+5];
vector<int> v[DX];
int search(int nod,int numar)
{
while(numar!=0 && nod!=0)
{
nod=stra[mp[inainte[numar]]][nod];
numar-=inainte[numar];
}
return nod;
}
void build(int nod,int nr)
{
int i,r;
for(i=1;put[i]<=nr;i++)
{
stra[i][nod]=stra[i-1][stra[i-1][nod]];
}
for(auto x: v[nod]) build(x,nr+1);
}
int main()
{
int a,b,n,m,aux,stop,i,j=1;
fin>>n>>m;
for(i=1;i<=n;i++)
{
fin>>stra[0][i];
v[stra[0][i]].push_back(i);
}
for(i=0;i<19;i++)
{
aux=(1<<i);
stop=(1<<(1+i));
put[i]=aux;
mp[aux]=i;
for(j=aux;j<stop && j<DX;j++) inainte[j]=aux;
}
for(i=1;i<=n;i++) if(stra[0][i]==0) build(i,0);
for(i=1;i<=m;i++)
{
fin>>a>>b;
fout<<search(a,b)<<"\n";
}
}