old_contents: # Time:  O(m + n)
  # Space: O(1)
  #
  # Write an efficient algorithm that searches for a value in an m x n matrix.
  # This matrix has the following properties:
  #
  # Integers in each row are sorted in ascending from left to right.
  # Integers in each column are sorted in ascending from top to bottom.
  # For example,
  #
  # Consider the following matrix:
  #
  # [
  #   [1,   4,  7, 11, 15],
  #   [2,   5,  8, 12, 19],
  #   [3,   6,  9, 16, 22],
  #   [10, 13, 14, 17, 24],
  #   [18, 21, 23, 26, 30]
  # ]
  # Given target = 5, return true.
  #
  # Given target = 20, return false.
  #
  
  class Solution:
      # @param {integer[][]} matrix
      # @param {integer} target
      # @return {boolean}
      def searchMatrix(self, matrix, target):
          m = len(matrix)
          if m == 0:
              return False
          
          n = len(matrix[0])
          if n == 0:
              return False
              
          count, i, j = 0, 0, n - 1
          while i < m and j >= 0:
              if matrix[i][j] == target:
                  return True
              elif matrix[i][j] > target:
                  j -= 1
              else:
                  i += 1
                  
          return False
  
new_contents: # Time:  O(m + n)
  # Space: O(1)
  #
  # Write an efficient algorithm that searches for a value in an m x n matrix.
  # This matrix has the following properties:
  #
  # Integers in each row are sorted in ascending from left to right.
  # Integers in each column are sorted in ascending from top to bottom.
  # For example,
  #
  # Consider the following matrix:
  #
  # [
  #   [1,   4,  7, 11, 15],
  #   [2,   5,  8, 12, 19],
  #   [3,   6,  9, 16, 22],
  #   [10, 13, 14, 17, 24],
  #   [18, 21, 23, 26, 30]
  # ]
  # Given target = 5, return true.
  #
  # Given target = 20, return false.
  #
  
  class Solution:
      # @param {integer[][]} matrix
      # @param {integer} target
      # @return {boolean}
      def searchMatrix(self, matrix, target):
          m = len(matrix)
          if m == 0:
              return False
          
          n = len(matrix[0])
          if n == 0:
              return False
              
          i, j = 0, n - 1
          while i < m and j >= 0:
              if matrix[i][j] == target:
                  return True
              elif matrix[i][j] > target:
                  j -= 1
              else:
                  i += 1
                  
          return False
  
subject: Update search-a-2d-matrix-ii.py