Cod sursa(job #3277979)

Utilizator Gullit_Ivan Matei Gullit_ Data 18 februarie 2025 12:44:41
Problema Range minimum query Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.89 kb
#include <bits/stdc++.h>
using namespace std;

const int MAXN=100000;
const int LOG=17;  //log2(100000)=16

int sp[MAXN][LOG];  
int lg[MAXN+1];  

void buildsparsetable(vector<int> &arr, int n) 
{
    for(int i=0; i<n; i++)
        sp[i][0]=arr[i];
    for(int j=1; (1<<j)<=n; j++) 
    {
        for(int i=0; i+(1<<j)<=n; i++) 
        {
            sp[i][j]=min(sp[i][j-1], sp[i+(1<<(j-1))][j-1]);
        }
    }
}

int query(int l, int r) 
{
    int k=lg[r-l+1];
    return min(sp[l][k], sp[r-(1<<k)+1][k]);
}

int main() 
{
    ifstream fin("rmq.in");
    ofstream fout("rmq.out");
    int n, m;
    fin>>n>>m;
    vector<int> v(n);
    for(int i=0; i<n; i++)
        fin>>v[i];
    lg[1]=0;
    for(int i=2; i<=n; i++)
        lg[i]=lg[i/2]+1;
    buildsparsetable(v, n);
    for(int i=0; i<m; i++)
    {
        int x, y;
        fin>>x>>y;
        fout<<query(x-1, y-1)<<'\n';  
    }
    return 0;
}