剑指 Offer 04. 二维数组中的查找

public boolean findNumberIn2DArray(int[][] matrix, int target) {
            int m = matrix.length;
            if(0 == m || null == matrix)return false;
            int n = matrix[0].length;
            int i = m - 1 , j = 0;
            while(i >= 0 && j < n)
            {
                if(matrix[i][j] == target)
                {
                    return true;
                }
                else if(matrix[i][j] > target)
                {
                    i--;
                }
                else
                {
                    j++;
                }
            }
            return false;
    }