Cod sursa(job #2562910)

Utilizator Tudor_PascaTudor Pasca Tudor_Pasca Data 29 februarie 2020 20:00:44
Problema Range minimum query Scor 90
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.14 kb
#include <iostream>
#include <fstream>

using namespace std;

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

int n, m;
int v[100001], tree[500005];

const int INF = 1e6;

void scan()
{
    in >> n >> m;

    for(int i = 1; i <= n; i++)
        in >> v[i];
}

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

    int mid = (l + r) / 2;
    int nl = node*2, nr = nl + 1;

    build(nl, l, mid);
    build(nr, mid+1, r);

    tree[node] = min(tree[nl], tree[nr]);
}

int query(int node, int l, int r, int ql, int qr)
{
    if(ql <= l && r <= qr)
        return tree[node];

    int mid = (l + r) / 2;
    int nl = node*2, nr = nl + 1;
    int rez = INF;

    if(ql <= mid)
        rez = min(rez, query(nl, l, mid, ql, qr));

    if(qr > mid)
        rez = min(rez, query(nr, mid+1, r, ql, qr));

    return rez;
}


int main()
{
    scan();

    build(1, 1, n);

    while(m--)
    {
        int x, y;

        in >> x >> y;

        //cout << x << ' ' << y << '\n';

        out << query(1, 1, n, x, y) << '\n';
    }

    return 0;
}