백준 1780 자바 및 C++

풀기 전:

이 문제도 마찬가지로 2630 풀이에다가 간단한 수정만 해주면 되는데

이 문제같은 경우 9개로 나누어야 하기때문에 일일히 하나하나 나열해서 재귀함수를 쓰는 대신

반복문안에다가 재귀함수를 넣었다.

자바(JAVA)

import java.io.*;
import java.lang.reflect.Array;
import java.util.*;
import java.util.Collections;
public class Main{
    static int arr[][];
    static int MinusCount;
    static int ZeroCount;
    static int PlusCount;
    public static boolean isAllSame(int startPosX,int startPosY,int n){
        int firstNum=arr[startPosX][startPosY];
        boolean Same=true;
        for(int i=startPosX;i<startPosX+n;i++){
            for(int j=startPosY;j<startPosY+n;j++){
                if(firstNum!=arr[i][j]){
                    Same=false;
                    break;
                }
            }
        }
        return Same;
    }
    public static void Divide(int startPosX,int startPosY,int n){
        if(n==1){
            if(arr[startPosX][startPosY]==-1){
                MinusCount++;
            }
            else if(arr[startPosX][startPosY]==0){
                ZeroCount++;
            }
            else {
                PlusCount++;
            }
            return;
        }
        else if(isAllSame(startPosX,startPosY,n)){
            if(arr[startPosX][startPosY]==-1){
                MinusCount++;
            }
            else if(arr[startPosX][startPosY]==0){
                ZeroCount++;
            }
            else {
                PlusCount++;
            }
            return;
        }
        else{
           for(int i=startPosX;i<startPosX+n;i+=n/3){
               for(int j=startPosY;j<startPosY+n;j+=n/3){
                   Divide(i,j,n/3);
               }
           }
        }
    }

    public static void main(String[] args) throws IOException {
        Scanner scanner=new Scanner(System.in);
        int n=scanner.nextInt();
        arr=new int[n][n];
        for(int i=0;i<n;i++){
            for(int j=0;j<n;j++){
                arr[i][j]=scanner.nextInt();
            }
        }
        Divide(0,0,n);
        System.out.println(MinusCount);
        System.out.println(ZeroCount);
        System.out.println(PlusCount);
    }
}

C++

#include <iostream>
#include <vector>
#include <cmath>
#include <algorithm>
#include <string>
using namespace std;
int** arr;
int PlusCount = 0;
int ZeroCount = 0;
int MinusCount = 0;
bool isAllSame(int startPosX, int startPosY, int n) {
    int firstNum = arr[startPosX][startPosY];
    bool Same = true;
    for (int i = startPosX; i < startPosX + n; i++) {
        for (int j = startPosY; j < startPosY + n; j++) {
            if (firstNum != arr[i][j]) {
                Same = false;
                break;
            }
        }
    }
    return Same;
}
void Divide(int startPosX, int startPosY, int n) {
    if (n == 1) {
        if (arr[startPosX][startPosY] == -1) {
            MinusCount++;
        }
        else if (arr[startPosX][startPosY] == 0) {
            ZeroCount++;
        }
        else {
            PlusCount++;
        }
        return;
    }
    else if (isAllSame(startPosX, startPosY, n)) {
        if (arr[startPosX][startPosY] == -1) {
            MinusCount++;
        }
        else if (arr[startPosX][startPosY] == 0) {
            ZeroCount++;
        }
        else {
            PlusCount++;
        }
        return;
    }
    else {
        for (int i = startPosX; i < startPosX + n; i += n / 3) {
            for (int j = startPosY; j < startPosY + n; j += n / 3) {
                Divide(i, j, n / 3);
            }
        }
    }
}
int main(void) {
    int n;
    cin >> n;
    arr = new int* [n];
    for (int i = 0; i < n; i++) {
        arr[i] = new int[n];
    }
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            cin >> arr[i][j];
        }
    }
    Divide(0, 0, n);
    cout << MinusCount << '\n' << ZeroCount<<'\n'<<PlusCount;

}

6개월 후에 다시 풀었을때:
이전에 했던 방식과 유사하지만 조금더 늘어썼다. 이전에서 n==1일때의 경우는 isAllSame에 포함되기에 생략했다.

import java.io.*;
import java.lang.reflect.Array;
import java.nio.Buffer;
import java.util.*;

public class Main {
    static int minus=0;
    static int zero=0;
    static int plus=0;
    static int arr[][];

    public static boolean isAllSame(int n,int first,int second){
        boolean same=true;
        int tmp=arr[first][second];
        for(int i=first;i<first+n;i++){
            for(int j=second;j<second+n;j++){
                if(tmp!=arr[i][j]){
                    same=false;
                }
            }
        }
        return same;
    }
    public static void divide(int n,int first,int second){
       if(isAllSame(n,first,second)){
           if(arr[first][second]==-1){
               minus++;
           }
           else if(arr[first][second]==0){
               zero++;
           }
           else{
               plus++;
           }
       }
       else{
           divide(n/3,first,second);
           divide(n/3,first,second+(n/3));
           divide(n/3,first,second+(n/3)*2);
           divide(n/3,first+(n/3),second);
           divide(n/3,first+(n/3),second+(n/3));
           divide(n/3,first+(n/3),second+(n/3)*2);
           divide(n/3,first+(n/3)*2,second);
           divide(n/3,first+(n/3)*2,second+(n/3));
           divide(n/3,first+(n/3)*2,second+(n/3)*2);
       }

    }
    public static void main(String[] args) throws IOException {
       Scanner scanner=new Scanner(System.in);
       int n=scanner.nextInt();
       arr=new int[n+1][n+1];
       for(int i=1;i<=n;i++){
           for(int j=1;j<=n;j++){
               arr[i][j]=scanner.nextInt();
           }
       }
       divide(n,1,1);
        System.out.println(minus);
        System.out.println(zero);
        System.out.println(plus);


    }

}