Cod sursa(job #998499)

Utilizator assa98Andrei Stanciu assa98 Data 17 septembrie 2013 10:41:37
Problema Plantatie Scor 0
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.33 kb
#include <cstdio>
#include <algorithm>
using namespace std;

const int MAX_N=510;

int m[MAX_N][MAX_N];

int rmax[10][MAX_N][MAX_N];

int lg[MAX_N];

int n,q;

void pregen() {
    for(int i=1;i<=n;i++) {
        for(int j=1;j<=n;j++) {
            rmax[0][i][j]=m[i][j];
        }
    }

    for(int k=1;(1<<k)<=n;k++) {
        for(int i=1;i+(1<<k)<=n;i++) {
            for(int j=1; j+(1<<k)<=n;j++) {
                rmax[k][i][j]=max(max(rmax[k-1][i][j],rmax[k-1][i][j+(1<<(k-1))]),
                                  max(rmax[k-1][i+(1<<(k-1))][j],rmax[k-1][i+(1<<(k-1))][j+(1<<(k-1))]));
            }
        }
    }

    lg[1]=0;
    for(int i=1;i<=n;i++) {
        lg[i]=lg[i>>1]+1;
    }
}

int query(int x,int y,int l) {

    int x2=x+l-1;
    int y2=y+l-1;

    l=lg[l];
    return max( max(rmax[l][x][y],rmax[l][x2-(1<<l)][y2-(1<<l)]),
            max(rmax[l][x][y2-(1<<l)],rmax[l][x2-(1<<l)][y]) );
}

int main()
{
    freopen("plantatie.in","r",stdin);
    freopen("plantatie.out","w",stdout);
    scanf("%d%d",&n,&q);
    for(int i=1;i<=n;i++) {
        for(int j=1;j<=n;j++) {
            scanf("%d",&m[i][j]);
        }
    }
    pregen();

    for(int i=1;i<=q;i++) {
        int x,y,k;
        scanf("%d%d%d",&x,&y,&k);
        printf("%d\n",query(x,y,k));
    }
    return 0;
}