Cod sursa(job #3213654)

Utilizator not_anduAndu Scheusan not_andu Data 13 martie 2024 12:33:46
Problema Range minimum query Scor 10
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.24 kb
#pragma GCC optimize ("03", "Ofast", "unroll-loops")
#include <bits/stdc++.h>

using namespace std;

#define INFILE "rmq.in"
#define OUTFILE "rmq.out"

typedef long long ll;

const int LOG_MAX = 22;
const int N_MAX = 1e5 + 5;

int n, queries;
int v[N_MAX];
int lg[LOG_MAX];
int rmq[LOG_MAX][N_MAX];

void init(){

    lg[1] = 0;
    for(int i = 1; i <= n; ++i){
        if(i != 1) lg[i] = lg[i >> 1] + 1;
        rmq[0][i] = v[i];
    }

    for(int bit = 1; bit <= lg[n]; ++bit){
        for(int i = 1; i + (1 << bit) - 1 <= n; ++i){
            rmq[bit][i] = min(rmq[bit - 1][i], rmq[bit - 1][i + (1 << (bit - 1))]);
        }
    }

}

int query(int left, int right){
    
    int dist = lg[right - left + 1];
    int minLeft = rmq[dist][left];
    int minRight = rmq[dist][right - (1 << dist) + 1];

    return min(minLeft, minRight);

}

void solve(){

    cin >> n >> queries;
    for(int i = 1; i <= n; ++i) cin >> v[i];

    init();

    for(int i = 0; i < queries; ++i){

        int left, right; cin >> left >> right;
        
        cout << query(left, right) << '\n';

    }

}

int main(){
    ios_base::sync_with_stdio(false);
    freopen(INFILE, "r", stdin);
    freopen(OUTFILE, "w", stdout);
    cin.tie(0), cout.tie(0);
    solve();
    return 0;
}