Leetcode:search a 2D Matrix problem solving report

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.

For example,

Consider the following matrix:

[  [1,   3,  5,  7],  [Ten, One,],  [23, 30, 34, 50]]

Given target = 3 , return true .

Solution 1:

Using the classic dichotomy template

1  while(Left <=Right ) {2             intMid = left + (right-left)/2;3             4          5             intn =Matrix[row][col];6             7             if(n = =target) {8                 ...9}Else if(N <target) {Tenleft = mid + 1; One}Else { Aright = Mid-1; -             } -}

1  Public classSolution {2      Public BooleanSearchmatrix (int[] Matrix,inttarget) {3         if(Matrix = =NULL|| Matrix.length = = 0 | | Matrix[0].length = = 0) {4             return false;5         }6         7         introws =matrix.length;8         intcols = matrix[0].length;9         Ten         intnum = rows *cols; One          A         intleft = 0; -         intright = Num-1; -          the          while(Left <=Right ) { -             intMid = left + (right-left)/2; -              -             intRow = mid/cols; +             intCol = mid%cols; -              +             intn =Matrix[row][col]; A              at             if(n = =target) { -                 return true; -}Else if(N <target) { -left = mid + 1; -}Else { -right = Mid-1; in             } -         } to          +         return false;  -     } the}

View CodeGITHUB:

Https://github.com/yuzhangcmu/LeetCode_algorithm/blob/master/divide2/SearchMatrix.java

Leetcode:search a 2D Matrix problem solving report