Cod sursa(job #3153181)

Utilizator maryyMaria Ciutea maryy Data 28 septembrie 2023 16:09:59
Problema Range minimum query Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.97 kb
#include <fstream>
using namespace std;
const int INF = 1e8;
const int nmax=100001;
int rmq[18][nmax], lg[nmax], n, m;
void PrecRmq()
{
  int x=lg[n];
  for(int i=1; i<=x; i++)
  {
    for(int j=1; j<=n-(1<<i)+1; j++)
    {
      rmq[i][j]=min(rmq[i-1][j], rmq[i-1][j+(1<<(i-1))]);
      //out<<rmq[i][j]<<" ";
    }
    //out<<"\n";
  }
}
int QueryRmq(int a, int b)
{
  int dif=(b-a+1);
  int x=a, rez=INF;
  int r;
  if(a==b) return rmq[0][a];
  while(dif!=0)
  {
    r=rmq[lg[dif]][x];
    rez=min(rez, r);
    //out<<dif<<" "<<lg[dif]<<" "<<r<<" "<<x<<"\n";
    x+=(1<<lg[dif]);
    dif=(b-x+1);
  }
  return rez;
}
int main()
{
    ifstream in("rmq.in");
    ofstream out("rmq.out");
    for(int i=2; i<=nmax; i++)
      lg[i]=lg[i/2]+1;
    in>>n>>m;
    for(int i=1; i<=n; i++)
    {
        in>>rmq[0][i];
    }
    PrecRmq();
    int l, r;
    for(int i=1; i<=m; i++)
    {
      in>>l>>r;
      out<<QueryRmq(l, r)<<"\n";
    }
}