Cod sursa(job #3295023)

Utilizator fernandodoneaDonea Fernando-Emanuel fernandodonea Data 1 mai 2025 18:31:36
Problema Range minimum query Scor 80
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.08 kb
#include <iostream>
#include <fstream>
using namespace std;

ifstream fin("rmq.in");
ofstream fout("rmq.out");



int v[int(1e5) + 1];
int rmq[int(1e5)+1][18];

int Log[int(1e5) + 1];


int queryMin(int l, int r){
    int diff = r - l + 1;
    int sol = 2147483647; // MAXINT
    for (int i = Log[diff]; i >= 0; i--){
        if ((1 << i) <= diff){
            sol = min(sol, rmq[l][i]);
            l += (1 << i);
            diff -= (1 << i);
        }
    }
    return sol;
}

int main()
{
    int n,m;

    fin>>n>>m;

    //read the array
    for(int i=1;i<=n;++i)
    {
        fin>>v[i];
    }

    //precompute log
    Log[1]=0;
    for(int i=2;i<=n;++i)
        Log[i]=Log[i/2]+1;

    //precompute rmq
    for(int i=1;i<=n;++i)
    {
        rmq[i][0]=v[i];
    }

    for(int j=1;j<=Log[n];++j)
    {
        for(int i=1; i + (1 << j) - 1 <= n; ++i)
        {
            rmq[i][j]= min(rmq[i][j-1], rmq[i+(1<<(j-1))][j - 1]);
        }
    }

   for(int i=1;i<=m;i++)
   {
        int x,y;
        fin>>x>>y;
        fout<<queryMin(x,y)<<endl;
   }
   fin.close();
   fout.close();
   return 0;

}