Cod sursa(job #3295800)

Utilizator adimiclaus15Miclaus Adrian Stefan adimiclaus15 Data 8 mai 2025 15:12:24
Problema Range minimum query Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.18 kb
#include <bits/stdc++.h>
using namespace std;

const int NMAX = 1e5;

int rmq[NMAX + 1][17];
int v[NMAX + 1];

ifstream f("rmq.in");
ofstream g("rmq.out");
//rmq[i][j] = minimul secventei care incepe la pozitia i si are lungime 2^j

int query_1(int x, int y) {
    int len = y - x + 1;
    int p = log2(len);
    //[x, y] = [x, x + 2^p - 1] U [y - 2^p + 1, y]
    return min(rmq[x][p], rmq[y - (1 << p) + 1][p]);
}

int query_log(int x, int y) {
    int len = y - x + 1;
    int mn = 1e9;
    for(int i = 0; (1 << i) <= len; i++) {
        if(len & (1 << i)) {
            mn = min(mn, rmq[x][i]);
            x += (1 << i);
        }
    }
    return mn;
}

int main() {
    int n, m;
    f >> n >> m;
    for(int i = 1; i <= n; i++) {
        f >> v[i];
    }

    //initializam coloana 0 din rmq cu valorile din v
    for(int i = 1; i <= n; i++) {
        rmq[i][0] = v[i];
    }

    for(int j = 1; j <= int(log2(n)); j++) {
        for(int i = 1; i <= n - (1 << j) + 1; i++) {
            rmq[i][j] = min(rmq[i][j - 1], rmq[i + (1 << (j - 1))][j - 1]);
        }
    }

    for(int i = 1; i <= m; i++) {
        int x, y;
        f >> x >> y;
        g << query_1(x, y) << '\n';
    }

	return 0;
}