Introduction
The Collections.shuffle function is a powerful tool in Java that allows you to randomly rearrange the elements of a collection. This can be useful for a variety of tasks, such as shuffling a deck of cards, randomly selecting elements from a list, or randomly generating numbers. The Collections.shuffle function is easy to use and can be a great way to add some randomness to your program.
Solution
The Collections.shuffle function is a Java utility method that randomly rearranges the elements of a given list. It takes a list as an argument and randomly shuffles the elements of the list. This is useful for creating random orderings of elements in a list, such as shuffling a deck of cards.
I don’t think you’re really asking about what Collections.shuffle does in general: I think you’re asking why Collections.shuffle affects the output:
You are creating a load of tasks of two kinds: one of them increments a value (“kind 1”); the other increments a value and sometimes prints a message (“kind 2”). These are put into a list, and executed sequentially.
If you put an equal number of these two kinds of tasks into a list, shuffle them, and execute them sequentially, the item at a position is going to be a “kind 1” task 50% of the time, and a “kind 2” task the rest of the time.
Since “kind 2” tasks only prints for a specific value, you will only get something printed if it is a “kind 2” task at position 2 * size - 1, which will be 50% of the time.
If you don’t shuffle them, but add “kind 1” and “kind 2” in turn, the item at position 2 * size - 1 will always be a “kind 2”, so it will always print.
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solved What does Collections.shuffle function do
The Collections.shuffle() function is a utility method in the Java Collections Framework that randomly rearranges the elements in a list. It takes a list as an argument and returns a randomly shuffled version of the list. This is useful for creating random orderings of elements, such as when dealing with a deck of cards or a list of numbers.
The Collections.shuffle() function works by randomly swapping elements in the list. It does this by looping through the list and randomly selecting two elements to swap. This process is repeated until all elements in the list have been swapped. The result is a randomly shuffled version of the original list.
The Collections.shuffle() function is useful for creating random orderings of elements. It can be used to create random orderings of cards in a deck, or to randomly select elements from a list. It can also be used to create random orderings of numbers, such as when creating a lottery draw.
The Collections.shuffle() function is an important part of the Java Collections Framework and is used in many applications. It is a simple and efficient way to create random orderings of elements in a list.