Write Java source code to take an integer n and returns the sum of all odd positive integers less than or equals to n. Please implement a sumOddo method for major functionality and a main method with input data for testing cases. Please pay attention to the neat coding style in Java, including grammar, indentations, naming of variables and methods, and comments. a) Conduct an experimental study regarding the running time of your Java code in nanoseconds. Please use excel to generate a chart/figure on the evaluation results. b) Analyze the time complexity and space complexity of your source code using asymptotic analysis. c) Is there a way that your algorithm can be further improved regarding time complexity and space complexity? Why or why not?

Write Four java programs (Snack.java, FruitSnack.java, SaltySnack.java, and OrderSystem.java. A Word document that includes a test table with test case #, input, expected output, actualoutput, and pass/fail columns. There should be at least 3 test cases. Make sure to includetest cases that validate data. Include a screen capture of running each test case. Include header comments that include your name, date, and description of the program. Include body comments. (1) There will be a Snack class with following attributes: id (combination of numbers and letters), size(values S, M, or L), and price(2) There will be two child classes FruitSnack and SaltySnack with the following additional attributes:o FruitSnack: It includes citrus fruit indication (value of this variable of is true or false)o SaltySnack: It includes nut snack indication (value of this variable of is true or false)(3) The Snack class hierarchy must provide the following functionality:• On creation, a snack instance must be…

Write a Java program that can simulate a simple calculator, using the Java console as the exclusive input and output device. That is, each input to the calculator, be it a number, like 12.34 or 1034, or an operator, like + or=, can be done on a separate line. After each such input, you should output to the Java console what would be displayed on your calculator.

You are given the following JavaDoc and asked to write the test cases for this method. You do not need to write the java code (JUnit); instead, you need to fill in the table with the inputs you choose for testing and justify your selection. You need to write only seven different/distinct test cases and explain why you have chosen the inputs for these cases. Note that no redundant or duplicate test cases are acceptable.