Given an integer N, the task is to print a number diamond of size N in rangoli style where N means till Nth number from number ‘1’.
Examples:
Input : 2 Output : --2-- 2-1-2 --2-- Input : 3 Output : ----3---- --3-2-3-- 3-2-1-2-3 --3-2-3-- ----3---- Input : 4 Output : ------4------ ----4-3-4---- --4-3-2-3-4-- 4-3-2-1-2-3-4 --4-3-2-3-4-- ----4-3-4---- ------4------
Approach:
First of all print from the first row till middle row, and then print from the row after middle row till the last row. The total number of positions in each row will be 4(N-1) + 1. Number of rows will be 2(N-1) + 1. Time complexity is O(N^2).
Below is the implementation.
def print_diamond(size): # print the first triangle # (the upper half) for i in range (size): # print from first row till # middle row rownum = i + 1 num_alphabet = 2 * rownum - 1 space_in_between_alphabets = num_alphabet - 1 total_spots = (2 * size - 1) * 2 - 1 total_space = total_spots - num_alphabet space_leading_trailing = total_space - space_in_between_alphabets lead_space = int(space_leading_trailing / 2) trail_space = int(space_leading_trailing / 2) # print the leading spaces for j in range(lead_space): print('-', end ='') # determine the middle character mid_char = (1 + size - 1) - int(num_alphabet / 2) # start with the last character k = 1 + size - 1 is_alphabet_printed = False mid_char_reached = False # print the numbers alternated by '-' for j in range(num_alphabet + space_in_between_alphabets): if not is_alphabet_printed: print(str(k), end ='') is_alphabet_printed = True if k == mid_char: mid_char_reached = True if mid_char_reached == True: k += 1 else: k -= 1 else: print('-', end ='') is_alphabet_printed = False # print the trailing spaces for j in range(trail_space): print('-', end ='') # go to the next line print('') # print the rows after middle row # till last row (the second triangle # which is inverted, i.e., the lower half) for i in range(size + 1, 2 * size): rownum = i num_alphabet = 2 * (2 * size - rownum) - 1 space_in_between_alphabets = num_alphabet - 1 total_spots = (2 * size - 1) * 2 - 1 total_space = total_spots - num_alphabet space_leading_trailing = total_space - space_in_between_alphabets lead_space = int(space_leading_trailing / 2) trail_space = int(space_leading_trailing / 2) # print the leading spaces for j in range(lead_space): print('-', end ='') mid_char = (1 + size - 1) - int(num_alphabet / 2) # start with the last char k = 1 + size - 1 is_alphabet_printed = False mid_char_reached = False # print the numbers alternated by '-' for j in range(num_alphabet + space_in_between_alphabets): if not is_alphabet_printed: print(str(k), end ='') is_alphabet_printed = True if k == mid_char: mid_char_reached = True if mid_char_reached == True: k += 1 else: k -= 1 else: print('-', end ='') is_alphabet_printed = False # print the trailing spaces for j in range(trail_space): print('-', end ='') # go to the next line print('') # Driver Code if __name__ == '__main__': n = 5 print_diamond(n) |
Output:
--------5-------- ------5-4-5------ ----5-4-3-4-5---- --5-4-3-2-3-4-5-- 5-4-3-2-1-2-3-4-5 --5-4-3-2-3-4-5-- ----5-4-3-4-5---- ------5-4-5------ --------5--------
