//-- https://www.codewars.com/kata/536a155256eb459b8700077e/train/javapublic class TheClockwiseSpiral{  private static final int UP = 0;  private static final int DOWN = 1;  private static final int LEFT = 2;  private static final int RIGHT = 3;  public static int[][] createSpiral(int N){    int[][] data = new int[N][N];    int toward = RIGHT;    for(int num=1,i=0,j=0; num <= N*N; num++){      data[i][j] = num;      switch(toward){      case UP:        if(i == 0 || data[i - 1][j] != 0){          toward = RIGHT;          j++;        }else{          i--;        }        break;      case DOWN:        if(i == N - 1 || data[i + 1][j] != 0){          toward = LEFT;          j--;        }else{          i++;        }        break;      case LEFT:        if(j == 0 || data[i][j - 1] != 0){          toward = UP;          i--;        }else{          j--;        }        break;      case RIGHT:        if(j == N -1 || data[i][j + 1] != 0){          toward = DOWN;          i++;        }else{          j++;        }        break;        }    }    return data;  }}

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