Cod sursa(job #2284572)

Utilizator SqueekDanielTodasca Daniel SqueekDaniel Data 17 noiembrie 2018 11:39:54
Problema Range minimum query Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.91 kb
#include <bits/stdc++.h>

#define MAXN   100005
#define LOGMAX 18

inline int log2(int x) {
    if (x == 1) return 0;
    return 1 + log2(x/2);
}

int N, M;
int V[MAXN];

int RMQ[LOGMAX][MAXN];
void ComputeRMQ() {
    for (int i=1; i<=N; ++i)
        RMQ[0][i] = V[i];

    for (int i=1, j, p=2; p<=N; ++i, p*=2)
        for (j=1; j+p-1<=N; ++j)
            RMQ[i][j] = std::min(RMQ[i-1][j], RMQ[i-1][j+p/2]);
}

int RMQQuery(int X, int Y) {
    int log = log2(Y-X+1);

    return std::min(RMQ[log][X], RMQ[log][Y-(1<<log)+1]);
}

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

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

void Rezolvare() {
    ComputeRMQ();

    int X, Y;
    while (M--) {
        In >> X >> Y;
        Out << RMQQuery(X, Y) << '\n';
    }
}

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

    return 0;
}