Cod sursa(job #3286746)

Utilizator unomMirel Costel unom Data 14 martie 2025 16:44:57
Problema Range minimum query Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.31 kb
#include <fstream>

using namespace std;

ifstream in("rmq.in");
ofstream out("rmq.out");
int n, q;
int v[100005];
int segtree[400005];

void build(int node, int left, int right)
{
    if(left == right)
    {
        segtree[node] = v[left];
    }
    else
    {
        int mij = (left + right) / 2;

        build(2*node, left, mij);
        build(2*node+1, mij + 1, right);

        segtree[node] = min(segtree[2*node], segtree[2*node+1]);
    }
}

int query(int node, int left, int right, int qleft, int qright)
{
    if(qleft <= left && right <= qright)
    {
        return segtree[node];
    }
    else
    {
        int mij = (left + right) / 2;

        if(qright <= mij)
        {
            return query(2*node, left, mij, qleft, qright);
        }
        else if(mij + 1 <= qleft)
        {
            return query(2*node+1, mij + 1, right, qleft, qright);
        }
        else
        {
            return min(query(2*node, left, mij, qleft, qright), query(2*node+1, mij + 1, right, qleft, qright));
        }
    }
}

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

    build(1, 1, n);

    int st, dr;
    while(q--)
    {
        in>>st>>dr;

        out<<query(1, 1, n, st, dr)<<'\n';
    }

    return 0;
}