Cod sursa(job #2581548)

Utilizator CosminMorarMorar Cosmin Andrei CosminMorar Data 15 martie 2020 14:32:40
Problema Range minimum query Scor 80
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.12 kb
#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("rmq.in");
ofstream fout("rmq.out");
int n, m;
int v[400100];

void update(int nod, int st, int dr, int pos, int value) {
    if (st == pos && pos == dr) {
        v[nod] = value;
        return;
    }

    int mij = (st + dr) / 2;

    if (pos <= mij)
        update(2 * nod, st, mij, pos, value);
    else
        update(2 * nod + 1, mij + 1, dr, pos, value);

    v[nod] = min(v[2 * nod], v[2 * nod + 1]);
}

int ask(int nod, int st, int dr, int a, int b) {
    if (a <= st && dr <= b)
        return v[nod];

    int mij = (st + dr) / 2;
    int sol = 2000000000;

    if (a <= mij)
        sol = min(sol, ask(2 * nod, st, mij, a, b));
    if (b > mij)
        sol = min(sol, ask(2 * nod + 1, mij + 1, dr, a, b));

    return sol;
}

int main() {
    fin >> n >> m;

    for (int i = 1; i <= n; i++) {
        int nr;
        fin >> nr;
        update(1, 1, n, i, nr);
    }

    for (int i = 1; i <= m; i++) {
        int a, b;
        fin >> a >> b;
        fout << ask(1, 1, n, a, b) << '\n';
    }
    return 0;
}