Cod sursa(job #2741825)

Utilizator Uriesu_IuliusUriesu Iulius Uriesu_Iulius Data 19 aprilie 2021 15:02:00
Problema Range minimum query Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.83 kb
#include <bits/stdc++.h>

using namespace std;

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

int n, m, lgn;
int v[100001], minq[100001][17], lgi[100001];

int query(int st, int dr)
{
    int j=lgi[dr-st+1];
    return min(minq[st][j], minq[dr-(1<<j)+1][j]);
}

int main()
{
    int i, j;
    fin >> n >> m;
    for(i=1; i<=n; i++)
        fin >> v[i];
    int cnt=0;
    for(i=2; i<=n; i++)
    {
        if(i==(1<<(cnt+1)))
            cnt++;
        lgi[i]=cnt;
    }
    lgn=log2(n);
    for(i=1; i<=n; i++)
        minq[i][0]=v[i];
    for(j=1; j<=lgn; j++)
        for(i=1; i+(1<<j)-1<=n; i++)
            minq[i][j]=min(minq[i][j-1], minq[i+(1<<(j-1))][j-1]);
    int st, dr;
    for(i=0; i<m; i++)
    {
        fin >> st >> dr;
        fout << query(st, dr) << '\n';
    }
    return 0;
}