Pagini recente » Cod sursa (job #339130) | Cod sursa (job #914042) | Cod sursa (job #3245832) | Cod sursa (job #69655) | Cod sursa (job #863272)
Cod sursa(job #863272)
#include <fstream>
#include <vector>
using namespace std;
ifstream fin("stramosi.in");
ofstream fout("stramosi.out");
vector<int> v[250001];
int n,m,x,y,arbdfs[250001],t[250001],intreaba[22][250001],nv[250001];
void query(int nod, int dist)
{
if(dist == 0)
{
fout<<nod<<'\n';
return;
}
int log = 0;
int i=1;
while(i*2<=dist)
{
i*=2;
log++;
}
query(intreaba[log][nod],dist-i);
}
int nivel;
void dfs(int nod)
{
arbdfs[nivel] = nod;
nv[nod] = nivel;
int log = 0;
int i = 1;
while(i<=nivel)
{
intreaba[log][nod] = arbdfs[nivel - i];
i*=2;
log++;
}
for(unsigned int i=0;i<v[nod].size();i++)
{
nivel++;
dfs(v[nod][i]);
nivel--;
}
}
int main()
{
fin>>n>>m;
for(int i=1;i<=n;i++)
{
fin>>t[i];
v[t[i]].push_back(i);
}
for(int i=1;i<=n;i++)
if(!t[i])
{
nivel = 0;
dfs(i);
}
for(int i=1;i<=m;i++)
{
fin>>y>>x;
if(x>nv[y])
fout<<"0"<<'\n';
else
query(y,x);
}
fin.close();
fout.close();
return 0;
}