Cod sursa(job #1477275)

Utilizator BogdanisarBurcea Bogdan Madalin Bogdanisar Data 25 august 2015 20:12:02
Problema Plantatie Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.58 kb
#include<iostream>
#include<fstream>
#include<cmath>
#include<algorithm>
#include<vector>
#include<bitset>
#include<cstring>
#include<queue>

#define ull unsigned long long
#define ll long long
#define pb push_back
#define FOR(a,b,c) for (int a=b;a<=c; ++a)
#define ROF(a,b,c) for (int a=b;a>=c; --a)

using namespace std;
ifstream f("plantatie.in");
ofstream g("plantatie.out");
int N,M;
int a[510][510],lg[510]; // lg[i]= logaritm de baza 2 din i
int rmq[510][510][15];
// range minimum query
// rmq[i][j][k]= maximul din patratul cu coltul stanga sus de coordonate (i,j) si cu latura 2^k

void preprocess();
int maxim(int,int);

int main()
{
    f>>N>>M;
    FOR (i,1,N) {
        FOR (j,1,N) {
            f>>a[i][j];
        }
    }
    FOR (i,2,N) {
        lg[i]=lg[i>>1]+1;
    }
    preprocess();
    while (M--) {
        int x,y,k;
        f>>x>>y>>k;
        int p=(1<<(lg[k]));
        g<<maxim(maxim(rmq[x][y][lg[k]],rmq[x+k-p][y][lg[k]]) , maxim(rmq[x][y+k-p][lg[k]],rmq[x+k-p][y+k-p][lg[k]]))<<'\n';
    }
    f.close();g.close();
    return 0;
}

void preprocess() {
    FOR (i,1,N) {
        FOR (j,1,N) {
            rmq[i][j][0]=a[i][j];
        }
    }
    for (int k=1;(1<<k)<=N;++k) {
        int p=(1<<(k-1));
        for (int i=1;i+p<=N;++i) {
            for (int j=1;j+p<=N;++j) {
                rmq[i][j][k]=maxim(maxim(rmq[i][j][k-1],rmq[i+p][j][k-1]) , maxim(rmq[i][j+p][k-1],rmq[i+p][j+p][k-1]));
            }
        }
    }
}

int maxim(int a,int b) {
    if (a>=b) {
        return a;
    }
    return b;
}