Cod sursa(job #3312518)

Utilizator andrei_nAndrei Nicolae andrei_n Data 28 septembrie 2025 19:51:43
Problema Range minimum query Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.6 kb
#include <bits/stdc++.h>
using namespace std;
ifstream fin ("rmq.in");
ofstream fout ("rmq.out");

int n, m;
int v[200001];
long long aint[800001];
const int INF = 2e9;

void build_aint(int node, int l, int r)
{
    if (l == r)
    {
        aint[node] = v[l];
        return;
    }

    int mid = (l + r) / 2;
    build_aint(2 * node, l, mid);
    build_aint(2 * node + 1, mid + 1, r);
    aint[node] = min(aint[2 * node], aint[2 * node + 1]);
}

long long query(int node, int ql, int qr, int l, int r)
{
    if (l > qr || r < ql)
        return INF;

    if (l >= ql && r <= qr)
        return aint[node];

    int mid = (l + r) / 2;
    long long rez1 = query(2 * node, ql, qr, l, mid);
    long long rez2 = query(2 * node + 1, ql, qr, mid + 1, r);

    return min(rez1, rez2);
}

long long query(int l, int r)
{
    return query(1, l, r, 1, n);
}

void update(int node, int l, int r, int poz, int x)
{
    if (l > poz || r < poz)
        return;

    if (l == r)
    {
        aint[node] = x;
        v[poz] = x;
        return;
    }

    int mid = (l + r) / 2;
    update(2 * node, l, mid, poz, x);
    update(2 * node + 1, mid + 1, r, poz, x);
    aint[node] = min(aint[2 * node], aint[2 * node + 1]);
}

void update(int poz, int x) //v[poz] = x
{
    return update(1, 1, n, poz, x);
}

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

    for (int i = 1; i <= m; i++)
    {
        int l, r;
        fin >> l >> r;
        fout << query(l, r) << '\n';
    }
    return 0;
}