38_decompression

 

const decompression = function (image) {
  let result = '';
  const decom = (x, y, len) => {
    let isSame = true;

    if(len === 1) {
      return '' + image[x][y];
    }

    for(let i=0; i<len; i++) {
      for(let j=0; j<len; j++) {
        if(image[x][y] !== image[x+i][y+j]) {
          isSame = false;
          break;
        }
      }
      if(!isSame) break;
    }
    if(isSame) return '' + image[x][y];

    len = len / 2;
    let str = 'X';
    str += decom(x, y, len);
    str += decom(x, y+len, len);
    str += decom(x+len, y, len);
    str += decom(x+len, y+len, len);
    
    return str;
  }
  result = decom(0,0,image.length);
  return result;
};

https://www.soyou.space/1d58f17d-3273-4d31-bd8a-0c7fabfad8a8