Cod sursa(job #2491438)

Utilizator ViAlexVisan Alexandru ViAlex Data 12 noiembrie 2019 16:45:40
Problema Plantatie Scor 10
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 1.71 kb
#include<bits/stdc++.h>
using namespace std;

ifstream in("plantatie.in");
ofstream out("plantatie.out");


int mat[500][500];
int query_table[10][500][500];
int n,m;

void read()
{
    in>>n>>m;
    for(int i=0; i<n; i++)
    {
        for(int k=0; k<n; k++)
        {
            in>>mat[i][k];
        }
    }
}

void create_lookup()
{
    for(int square_size=0; (1<<square_size)<n; square_size++)
    {
        for(int y=0; y<n-(1<<square_size)+1; y++)
        {
            for(int x=0; x<n-(1<<square_size)+1; x++)
            {
                if(square_size==0)
                {
                    query_table[square_size][y][x]=mat[y][x];
                }
                else
                {
                    int last=1<<(square_size-1);
                    int a=query_table[square_size-1][y][x];
                    int b=query_table[square_size-1][y][x+last];
                    int c=query_table[square_size-1][y+last][x];
                    int d=query_table[square_size-1][y+last][x+last];
                    query_table[square_size][y][x]=max(max(a,b),max(c,d));
                }
            }
        }
    }
}


int get_max_in_square(int x,int y,int length)
{
    int logbase=log2(length-1);



    int a=query_table[logbase][y][x];


    int b=query_table[logbase][y][(x+length-1)-(1<<logbase)+1];


    int c=query_table[logbase][(y+length-1)-(1<<logbase)+1][x];


    int d=query_table[logbase][(y+length-1)-(1<<logbase)+1][(x+length-1)-(1<<logbase)+1];


    return max(max(a,b),max(c,d));

}

void solve()
{
    int a,b,c;
    for(int i=0; i<m; i++)
    {
        in>>a>>b>>c;
        out<<get_max_in_square(b-1,a-1,c)<<'\n';
    }

}


int main()
{
    read();
    create_lookup();
    solve();
    return 0;
}