#!usr/bin/env python
#encoding:utf-8
'''''
__Author__:沂水寒城
功能：zigzag_pattern
T  W  Q  K
N D X Z S V B
G  A  C
convert("TNGDWXAZQSCVBK", 3) should return "TWQBNDXZSVKGAC".
'''
def convert_test(one_str,num):
  '''''
  '''
  mod=len(one_str)%(num+1)
  if mod==0:
    cols=(len(one_str)/(num+1))*2
  else:
    cols=(len(one_str)/(num+1))*2+1
  rows=num
  #print 'rows, cols', rows, cols
  matrix=[]
  for i in range(rows):
    matrix.append([0]*cols)
  one_str_list=list(one_str)
  for j in range(cols):
    if j%2==0:
      for i in range(rows):
        if len(one_str_list):
          matrix[i][j]=one_str_list.pop(0)
    else:
      matrix[1][j]=one_str_list.pop(0)
  #print matrix
  # for one in matrix:
  #   one_list=[str(onec) for onec in one]
  #   print ' '.join(one_list)
  res=''
  for one_list in matrix:
    one_list=[str(one) for one in one_list]
    res+=''.join(one_list)
  return ''.join(res.split('0'))
if __name__ == '__main__':
  print convert_test("TNGDWXAZQSCVBK", 3)
  print convert_test("PAYPALISHIRING", 2)
  print convert_test("PAYPALISHIRING", 4)