class_docstr: Calculate the Munkres solution to the classical assignment problem.
  See the module documentation for usage.
docstr: Find the first uncovered element with value 0
docstr_tok: ["Find","the","first","uncovered","element","with","value","0"]
code: def __find_a_zero(self):
      """Find the first uncovered element with value 0"""
      row = -1
      col = -1
      i = 0
      n = self.n
      done = False
  
      while not done:
          j = 0
          while True:
              if (
                  (self.C[i][j] == 0)
                  and (not self.row_covered[i])
                  and (not self.col_covered[j])
              ):
                  row = i
                  col = j
                  done = True
              j += 1
              if j >= n:
                  break
          i += 1
          if i >= n:
              done = True
  
      return (row, col)
  
imports: import sys
label_desc: Use image node_id 14 for calling the Munkres obj's underlying member method code with example usage: obj.__find_a_zero() and returns: row,  col