Cod sursa(job #2380608)

Utilizator RaresLiscanLiscan Rares RaresLiscan Data 15 martie 2019 11:40:20
Problema Range minimum query Scor 60
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.14 kb
#include <bits/stdc++.h>
#define maxArb 200005
#define maxN 100005

using namespace std;

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

int v[maxN], a[maxArb];

void initialize (int node, int b, int e)
{
    if (b == e) a[node] = b;
    else {
        initialize(2 * node, b, (b + e) / 2);
        initialize(2 * node + 1, (b + e) / 2 + 1, e);
        if (v[a[2 * node]] <= v[a[2 * node + 1]]) a[node] = a[2 * node];
        else a[node] = a[2 * node + 1];
    }
}

int query (int node, int b, int e, int i, int j)
{
    if (i > e || j < b) return -1;
    if (i <= b && e <= j) return a[node];
    int p1 = query(2 * node, b, (b + e) / 2, i, j), p2 = query(2 * node + 1, (b + e) / 2 + 1, e, i, j);
    if (p1 == -1) return p2;
    if (p2 == -1) return p1;
    if (v[p1] <= v[p2]) return p1;
    else return p2;
}

int main()
{
    int n, m;
    fin >> n >> m;
    for (int i = 1; i <= n; i ++) fin >> v[i];
    int b = 1, e = n, node = 1;
    initialize(node, b, e);
    int x, y;
    for (int i = 1; i <= m; i ++) {
        fin >> x >> y;
        fout << v[query(node, b, e, x, y)] << "\n";
    }
    return 0;
}