CSE 142

Check-in Meeting

Week 4

Write a method called fractionSum that accepts an integer parameter n and returns as a double the sum of the first n terms of the sequence. In other words, the method should generate the following sequence: 1 + (1/2) + (1/3) + (1/4) + (1/5) + ... You may assume that the parameter n is non-negative.
Write a method named repl that accepts a String and a number of repetitions as parameters and returns the String concatenated that many times. For example, the call repl("hello", 3); returns "hellohellohello". If the number of repetitions is 0 or less, an empty string is returned.
Write a method named evenSum that prompts the user for a number of integers and prints the total even sum and maximum of the even numbers. You may assume that the user types at least one non-negative even integer.

how many integers? 4
next integer? 2
next integer? 9
next integer? 18
next integer? 4
even sum = 24
even max = 18

Write a method named numUnique that takes three integers as parameters and returns the number of unique integers among the three. For example, the call numUnique(18, 3, 4); should return 3 because the parameters have 3 different values. By contrast, the call numUnique(6, 7, 6); would return 2 because there are only 2 unique numbers among the three parameters: 6 and 7.
A "perfect number" is a positive integer that is the sum of all its proper factors (that is, factors including 1 but not the number itself). The first two perfect numbers are 6 and 28, since 1+2+3=6 and 1+2+4+7+14=28. Write a static method perfectNumbers that takes an integer max as an argument and prints out all perfect numbers that are less than or equal to max.

Here is the console output from a call to perfectNumbers(6);

Perfect numbers up to 6: 6

Here is the console output from a call to perfectNumbers(500);

Perfect numbers up to 500: 6 28 496