【LeetCode】 240. Search a 2D Matrix II

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.

public class Solution {    public boolean searchMatrix(int[][] matrix, int target) {        if (matrix.length == 0 || matrix[0].length == 0) {            return false;        }        int row = 0, col = matrix[0].length - 1;        while (row <= matrix.length - 1 && col >= 0) {            if (target == matrix[row][col]) {                return true;            } else if (target < matrix[row][col]){                col--;            } else {                row++;            }        }        return false;    }}