Finding a 2D Array

题目：
在一个 n * m 的二维数组中,每一行都按照从左到右递增的顺序排序,每一列都按照从上到下递增的顺序排序.请完成一个高效的函数,输入这样的一个二维数组和一个整数,判断数组中是否含有该整数.
现有矩阵 matrix 如下：

[
[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]
]
给定 target = 5,返回 true.
分析：
从左下角开始查找,Subtract the number of rows if the current number is greater than the target value1,The number of columns is added if the current number is less than the target value1,until the target value is found.

代码：

public class FindNumberIn2DArray {
    
    public boolean findNumberIn2DArray(int[][] matrix, int target) {
    
    //Remember not to forget this judgment on the array
     if(matrix == null || matrix.length <= 0 || matrix[0].length <= 0){
    
            return false;
        }
        int rows = matrix.length;
        int cols = matrix[0].length;
        //Determine the position of the lower left corner
        int row = rows-1;
        int col = 0;
        while (row >= 0 && col <= cols - 1){
    
            if (target > matrix[row][col]){
    
                col++;
            }else if(target < matrix[row][col]){
    
                row--;
            }else {
    
                return true;
            }
        }
        return false;
    }
}