Cod sursa(job #2376273)

Utilizator SqueekDanielTodasca Daniel SqueekDaniel Data 8 martie 2019 14:37:19
Problema Range minimum query Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.89 kb
#include <bits/stdc++.h>

#define MAXN 100005
#define LOGN 18

int N, M;
int LOG2[MAXN];
int RMQ[LOGN][MAXN];

void ComputeLOG2() {
    for (int i=2; i<=N; ++i)
        LOG2[i] = LOG2[i/2] + 1;
}

void ComputeRMQ() {
    for (int i=1, j; (1<<i) <= N; ++i)
        for (j=1; j + (1<<i)-1 <= N; ++j)
            RMQ[i][j] = std::min(RMQ[i-1][j], RMQ[i-1][j + (1<<(i-1))]);
}

int Query(int X, int Y) {
    if (X > Y) std::swap(X, Y);
    int K = LOG2[Y-X+1];
    return std::min(RMQ[K][X], RMQ[K][Y - (1<<K)+1]);
}

std::ifstream In ("rmq.in");
std::ofstream Out("rmq.out");

void Citire() {
    In >> N >> M;
    for (int i=1; i<=N; ++i)
        In >> RMQ[0][i];
}

void Rezolvare() {
    ComputeLOG2();
    ComputeRMQ();
    int X, Y;
    while (M--)
        In >> X >> Y, Out << Query(X, Y) << '\n';
}

int main()
{
    Citire();
    Rezolvare();

    return 0;
}