誰でもこのコードのロジックを説明できますか？奇妙な順序の魔方陣を作成するプログラムです

Question

public void odd(int[][] magic) { 
    int N = magic.length; 
    int row = N - 1; 
    int col = N/2; 
    magic[row][col] = 1; 
    for (int i = 2; i <= N * N; i++) { 
    if (magic[(row + 1) % N][(col + 1) % N] == 0) { 
     row = (row + 1) % N; 
     col = (col + 1) % N; 
    } else { 
     row = (row - 1 + N) % N; 
    } 
    magic[row][col] = i; 
    } 
} 

私は 'if'ステートメントを理解できません。

Answer 1

私はそれを説明しようとした

（私は、コメントを使用したコードを参照してください）

public static void main(String[] args) { 


    int[][] magic = new int[7][5]; //<<Create a new Bidimentional Array 
    odd(magic); 
} 

public static void odd(int[][] magic) { 
     int N = magic.length; //it will take the length in position 0 from array well the 7 [7][5] so if i use [2][10] it will 2 the length DON'T TRY USE [0][n] or u'll get an error 
     int row = N - 1; // 7 - 1 = 6 (or your value used [VALUE_TAKEN][n]) 
     int col = N/2; // 7/2 = 3 (or your value used [VALUE_TAKEN][n]) 
     magic[row][col] = 1; //Here you get an error if you used [0][n], BUT if you used [7][5] well it will say magic[6][3] = 1 
     for (int i = 2; i <= N * N; i++) { //for i=2 ; i < 14; i ++ 
     if (magic[(row + 1) % N][(col + 1) % N] == 0) { // (col + 1) % N] = 0,(col + 1) % N] = 4, so if magic[0,4] == 0 enter 
      row = (row + 1) % N; //SO IF IT'S TRUE YOU ENTER 
      col = (col + 1) % N; 
     } else { 
      row = (row - 1 + N) % N; //it was not true 
     } 
     magic[row][col] = i; //no matter what you will be here 
     } 
    }