Solution

The Fisher-Yates shuffle algorithm, also known as the Knuth shuffle, is an algorithm for generating a random permutation of a finite sequence—in other words, for shuffling the sequence. The algorithm produces an unbiased permutation: every permutation is equally likely. The modern version of the Fisher-Yates shuffle, designed for computer use, was introduced by Richard Durstenfeld in 1964 and popularized by Donald E. Knuth.

We can think of deck of cards as the array of integers with indices lying from 0 to 51, as there are 52 cards.

Algorithm

Here's a rundown of how the Fisher-Yates shuffle algorithm works:

Start from the last element: Begin with the last element in the array (let's call this array A) and the last element's index n - 1, where n is the length of the array.
Pick a random element: Select a random index j such that 0 <= j <= i where i starts at n - 1 and decreases by 1 in each iteration. A good pseudo-random number generator is used to ensure fairness.
Swap elements: Swap the element at index i with the element at index j. If i is equal to j, the swap is essentially a no-op.
Decrease

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