Cod sursa(job #3349912)

Utilizator adimiclaus15Miclaus Adrian Stefan adimiclaus15 Data 3 aprilie 2026 14:49:25
Problema Range minimum query Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.29 kb
#include <bits/stdc++.h>
using namespace std;

const int NMAX = 1e5;
int D[NMAX + 1][18];
//D[i][j] = minimul pe intervalul care incepe la i si are lungime 2^j
//D[i][j] = min(D[i][j - 1], D[i + 2^(j - 1)][j - 1])
//log2(i) = log2(i / 2) + 1
int L[NMAX + 1];

int query1(int x, int y) {
    int len = y - x + 1;
    //int p = L[len];
    int p = log2(len);
    int a = D[x][p]; //[x, x + 2^p - 1]
    int b = D[y - (1 << p) + 1][p]; //[y - 2^p + 1, y]
    return min(a, b);
}

int query2(int x, int y) {
    int len = y - x + 1;
    int mn = 1e9;
    for(int p = L[len]; p >= 0 && len > 0; p--) {
        if((1 << p) <= len) {
            mn = min(mn, D[x][p]);
            x += (1 << p);
            len -= (1 << p);
        }
    }
    return mn;
}

int main() {
    ifstream cin("rmq.in");
    ofstream cout("rmq.out");
    int n, q;
    cin >> n >> q;
    //L[1] = 0;
    for(int i = 1; i <= n; i++) {
        cin >> D[i][0];
        // if(i > 1) {
        //     L[i] = L[i / 2] + 1;
        // }
    }
    for(int j = 1; (1 << j) <= n; j++) {
        for(int i = 1; i + (1 << j) - 1 <= n; i++) {
            D[i][j] = min(D[i][j - 1], D[i + (1 << (j - 1))][j - 1]);
        }
    }
    for(int i = 1; i <= q; i++) {
        int x, y;
        cin >> x >> y;
        cout << query1(x, y) << '\n';
    }
	return 0;
}