[Leetcode] (python): 074-search a 2D Matrix

Source of the topic

https://leetcode.com/problems/search-a-2d-matrix/

Write an efficient algorithm, searches for a value in a m x n Matrix. This matrix has the following properties:

• Integers in each row is sorted from the left to the right.
• The first integer of each row was greater than the last integer of the previous row.

Test instructions Analysis

Input:a Matrix and a target to query

Output:true or False

Conditions: Find an element in a matrix, notice that the matrix is ordered

Topic ideas

Find out which column to locate in column two, and then double-click the boundary condition.

PS: In fact, directly in the column search, found low-1 less than 0 o'clock, directly return false can be, but the paste code can be ported to the insertion element of the binary ordering inside, in order to unify there is no change.

AC Code (PYTHON)

1 __author__='YE'2 3 classsolution (object):4     defSearchmatrix (self, Matrix, target):5         """6 : Type Matrix:list[list[int]]7 : Type Target:int8 : Rtype:bool9         """Tenm =len (Matrix) Onen =Len (matrix[0]) ALow =0 -High = M-1 -  the          whileLow <=High : -Mid = (low + high)/2 -             ifMatrix[mid][0] = =Target: -                 returnTrue +             elifMatrix[mid][0] >Target: -High = Mid-1 +             Else: ALow = mid + 1 atrow = Low-1 -         ifRow <0: -row =0 -  -Low =0 -High = N-1 in  -          whileLow <=High : toMid = (low + high)/2 +             ifMatrix[row][mid] = =Target: -                 returnTrue the             elifMatrix[row][mid] >Target: *High = Mid-1 $             Else:Panax NotoginsengLow = mid + 1 -         returnFalse the  +Matrix = [[1,3,5,7],[10,11,16,20],[23,30,34,50]] Atarget = 16 the Print(Solution (). Searchmatrix (Matrix,target))

[Leetcode] (python): 074-search a 2D Matrix