Cod sursa(job #2773854)

Utilizator IoanMihaiIoan Mihai IoanMihai Data 8 septembrie 2021 23:17:09
Problema Range minimum query Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.84 kb
#include <bits/stdc++.h>
using namespace std;
ifstream fin("rmq.in");
ofstream fout("rmq.out");

#define NMAX 100005
#define LMAX 18

int lookup[LMAX][NMAX];
int n, m, l;
int lg[NMAX];
int a[NMAX];

int main() {
    fin >> n >> m;
    for (int i=1;i<=n;i++){
        fin >> a[i];
    }

    lg[1] = 0;
    for (int i=2;i<=n;i++){
        lg[i] = lg[i/2] + 1;
    }

    for (int i=1;i<=n;i++) {
        lookup[0][i] = a[i];
    }

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

    int x, y, diff, sh;
    for (int i=1;i<=m;i++){
        fin >> x >> y;
        diff = y - x + 1;
        l = lg[diff];
        sh = diff - (1 << l);
        fout << min(lookup[l][x], lookup[l][x + sh]) << '\n';
    }
    return 0;
}