Cod sursa(job #2679740)

Utilizator tudorbuhniaTudor Buhnia tudorbuhnia Data 1 decembrie 2020 13:26:43
Problema Stramosi Scor 60
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 0.85 kb
#include <fstream>
#include <vector>
using namespace std;
int v[250005][18],vp[20];
int main()
{
    ifstream cin("stramosi.in");
    ofstream cout("stramosi.out");
    int n,m,x,y,i,k,r,kk;
    cin >> n >> m;
    for(int i=1;i<=n;i++)
    {
        cin >> x;
        if(x>0)
            v[i][0]=x;
    }
    for(int j=1;j<=n;j++)
    {
        x=j;
        i=1;
        while(1)
        {
            v[x][i]=v[v[x][i-1]][i-1];
            if(v[x][i]==0)
                break;
            i++;
        }
    }
    for(int i=0;i<18;i++)
        vp[i]=(1 << i);
    for(int j=1;j<=m;j++)
    {
        cin >> x >> y;
        i=0;
        while(v[x][i+1]>0 && vp[i+1]<=y)
            i++;
        k=vp[i];
        r=v[x][i];
        for(int i=k+1;i<=y;i++)
            r=v[r][0];
        cout << r << '\n';
    }
    return 0;
}