문제 링크

정답 :

def solution(arr):
    row = len(arr)
    col = len(arr[0])
    
    if row > col:
        for i in range(row):
            arr[i] += [0] * (row - col)
    elif row < col:
        for i in range(row, col):
            arr.append([0] * col)
            
    return arr