Cod sursa(job #3205045)

Utilizator stefangab95Muscalu Stefan Gabriel stefangab95 Data 18 februarie 2024 18:03:55
Problema Range minimum query Scor 30
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.16 kb
#include <fstream>
#include <vector>
#include <algorithm>

using namespace std;

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

int n, m;
vector<int> arr;
vector<vector<int>> st;

void build(int node, int L, int R) {
    if (L == R) {
        st[node].push_back(arr[L]);
    } else {
        build(node * 2 + 1, L, (L + R) / 2);
        build(node * 2 + 2, (L + R) / 2 + 1, R);
        merge(st[node * 2 + 1].begin(), st[node * 2 + 1].end(), st[node * 2 + 2].begin(), st[node * 2 + 2].end(), back_inserter(st[node]));
    }
}

int query(int node, int L, int R, int i, int j) {
    if (i > R || j < L) return INT32_MAX;
    if (i <= L && R <= j) return *min_element(st[node].begin(), st[node].end());

    int mid = (L + R) / 2;
    return min(query(node * 2 + 1, L, mid, i, j), query(node * 2 + 2, mid + 1, R, i, j));
}

int main() {
    fin >> n >> m;
    arr.resize(n);
    st.resize(4 * n);

    for (int i = 0; i < n; ++i) {
        fin >> arr[i];
    }

    build(0, 0, n - 1);

    for (int i = 0; i < m; ++i) {
        int x, y;
        fin >> x >> y;
        fout << query(0, 0, n - 1, x - 1, y - 1) << "\n";
    }

    return 0;
}