Cod sursa(job #2455632)

Utilizator mihaimodiMihai Modi mihaimodi Data 12 septembrie 2019 10:13:48
Problema Range minimum query Scor 80
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.09 kb
#include <fstream>
#include <cmath>
#include <climits>
using namespace std;
ifstream fin("rmq.in");
ofstream fout("rmq.out");
int v[100001],dp[100001][20];
int lg[20];
int n,m,st,dr,k,dif,Min,p;
int main()
{
    //preprocesare
    lg[0]=1;
    for(int i=1;i<=17;i++)
        lg[i]=lg[i-1]*2;

    fin>>n>>m;
    for(int i=1;i<=n;i++)
    {
        fin>>v[i];
        dp[i][0]=v[i];
    }
    int log2n=log2(n)+1;
    for(int j=1;j<=log2n;j++)
    {
        for(int i=1;i<=n;i++)
            if(i+(1<<(j-1))<=n)
            {
                if(dp[i][j-1]<dp[i+(1<<j-1)][j-1])
                    dp[i][j]=dp[i][j-1];
                else
                    dp[i][j]=dp[i+(1<<j-1)][j-1];
            }
    }
    for(int i=1;i<=m;i++)
    {
        fin>>st>>dr;
        dif=dr-st+1, Min=INT_MAX;
        while(dif>0)
        {
            k=0;
            while(lg[k]<=dif)
                k++;
            k--;
            Min=min(Min,dp[st][k]);
            p=(1<<k);
            dif-=p,st+=p;
        }
        fout<<Min<<'\n';
    }
    //
    return 0;
}