array-shuffle-java

TDD Kata

• Exercise: Array Shuffle
• Language & test-framework: Java, JUnit
• Status: Done

Problem description

Write a program to shuffle an array.

Start by writing a function which will accept two integer arguments (min,max) and generate a random integer between min and max where:

• min is an inclusive lower bound
• max is an exclusive upper bound

For example (1,7) should generate random integers from {1,2,3,4,5,6} suitable for a dice roll. How will you test this?

Use this function to write shuffle:

• Iterate through the array and for each element[i]
• generate a random integer (min=r,max=array.size)
• swap the integers at indexes i and r

The shuffle function

• does not mutate the array argument
• returns an array
• the returned array is randomly shuffled!
• the returned array is a permutation of the array argument