Cod sursa(job #2408119)

Utilizator AlexandruBrezuleanuAlexandruBrezuleanu AlexandruBrezuleanu Data 17 aprilie 2019 17:12:30
Problema Range minimum query Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.87 kb
#include <bits/stdc++.h>
#define MAX 100100
#define LOGMAX 20
using namespace std;
ifstream fin("rmq.in");
ofstream fout("rmq.out");
int a[MAX];
int c[MAX][LOGMAX];
int n,m;
void process();
int query(int i,int j);
int main()
{
    int i,x,y;
    fin>>n>>m;
    for(i=1;i<=n;i++)
        fin>>a[i];
    process();
    for(i=1;i<=m;i++)
    {
        fin>>x>>y;
        fout<<query(x,y)<<'\n';
    }
    return 0;
}

void process()
{
    int i,j;
    for(i=1;i<=n;i++)
        c[i][0]=i;
    for(j=1;(1<<j)<=n;j++)
        for(i=1;i+(1<<j)-1<=n;i++)
        if(a[c[i][j-1]]<a[c[i+(1<<j-1)][j-1]])
        c[i][j]=c[i][j-1];
        else
            c[i][j]=c[i+(1<<j-1)][j-1];
}
int query(int i,int j)
{
    int k;
    k=log2(j-i+1);
    if(a[c[i][k]]<a[c[j-(1<<k)+1][k]])
        return a[c[i][k]];
    else
        return a[c[j-(1<<k)+1][k]];
}