Cod sursa(job #3132629)

Utilizator cincadavidCinca David Andrei cincadavid Data 23 mai 2023 12:22:00
Problema Range minimum query Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.01 kb
#include <fstream>
#include <vector>
#include <algorithm>
#include <math.h>

using namespace std;

ifstream cin("rmq.in");
ofstream cout("rmq.out");

vector<vector<int> >sparse;
int lg[100000];

void Build(vector<int>&v,int n)
{
    for(int i=0;i<n;i++)
    {
        sparse[i][0]=v[i];
    }
    for(int j=1;j<=lg[n];j++)
    {
        for(int i=0;i+(1<<j)-1<n;i++)
        {
            sparse[i][j]=min(sparse[i][j-1],sparse[i+(1<<(j-1))][j-1]);
        }
    }
}

int Query(int l,int r)
{
    int length=r-l+1;
    return min(sparse[l][lg[length]],sparse[l+length-(1<<lg[length])][lg[length]]);
}

int main()
{
    int n,m;
    for(int i=2;i<=100000;i++)
    {
        lg[i]=lg[i/2]+1;
    }
    cin>>n>>m;
    vector<int>v(n);
    sparse.resize(n+1,vector<int>(lg[n]+1));


    for(int i=0;i<n;i++)
    {
        cin>>v[i];
    }

    Build(v,n);
    int a,b;
    for(int i=0;i<m;i++)
    {
        cin>>a>>b;
        cout<<Query(a-1,b-1)<<"\n";
    }

    return 0;
}