Cod sursa(job #1403423)

Utilizator dumitrualexAlex Dumitru dumitrualex Data 27 martie 2015 11:52:34
Problema Range minimum query Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.19 kb
#include <cstdio>
#include <algorithm>

using namespace std;

int N, M, L;
int * v;
int ** dp;

inline int log2(int x)
{
    int i = -1;
    while (x)
    {
        x >>= 1;
        i++;
    }
    if (i == -1)
        i = 0;
    return i;
}

void debug()
{
    int i, j;

    for (i = 0; i <= L; i++)
    {
        for (j = 1; j <= N-((1<<i)-1); j++)
            printf("%d ", dp[i][j]);
        printf("\n");
    }
}

int main()
{
    freopen("rmq.in", "r", stdin);
    freopen("rmq.out", "w", stdout);

    int i, j;
    int a, b;
    int lungime, mijloc;
    scanf("%d%d", &N, &M);

    L = log2(N);
    v = new int[N+5];
    dp = new int * [L+5];

    for (i = 1; i <= N; i++)
    {
        scanf("%d", &v[i]);
    }

    dp[0] = v;
    for (i = 1; i <= L; i++)
    {
        dp[i] = new int [N+5];
        for (j = 1; j + (1<<i)-1 <= N; j++)
            dp[i][j] = min(dp[i-1][j], dp[i-1][j+(1<<(i-1))]);
    }

    for (i = 1; i <= M; i++)
    {
        scanf("%d%d", &a, &b);
        lungime = b-a;
        mijloc = b-(1<<log2(lungime))+1;

        printf("%d\n", min(dp[log2(lungime)][a], dp[log2(lungime)][mijloc]));
    }
    return 0;
}