Cod sursa(job #1218772)

Utilizator gabrielinelusGabriel-Robert Inelus gabrielinelus Data 12 august 2014 14:57:04
Problema Range minimum query Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.01 kb
#include <cstdio>
#include <cmath>
#include <algorithm>

using namespace std;
int N,M;
int DP[17][100005]; /// DP[i][j] -> minimul unei secvente de 2^i caractere care incepe pe pozitia j

void read( void )
{
    scanf("%d%d",&N,&M);
    for(int i = 1; i <= N; ++i)
        scanf("%d",&DP[0][i]);
}

void precalc( void )
{
    int lg = log2(N);
    for(int i = 1; i <= lg; ++i)
        for(int j = 1; j <= N; ++j)
            if(j + (1 << i) - 1 > N)
                DP[i][j] = DP[i-1][j];
            else
                DP[i][j] = min(DP[i-1][j],DP[i-1][j+(1<<(i-1))]);
}

int Querry(int a,int b)
{
    int lung = b-a+1,lg;
    lg = log2(lung);
    return min(DP[lg][a],DP[lg][ b - (1<<lg) + 1]);
}

void solve()
{
    int a,b;
    for(int i = 1; i <= M; ++i)
    {
        scanf("%d%d",&a,&b);
        printf("%d\n",Querry(a,b));
    }
}

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

    read();
    precalc();
    solve();

    return 0;
}