Community

Start a Thread


Notifications
Subscribe You’re not receiving notifications from this thread.

Next Permutation (Main Thread)

Here is the interview question prompt, presented for reference.

A permutation of a set, in mathematics, is an ordering of its elements into a series or linear sequence or a reordering of its elements if such a set is already sorted. The technique or method of altering an ordered set's linear arrangement is called permutation.

![Permutation of 3 distinct colors](https://storage.googleapis.com/algodailyrandomassets/curriculum/next-permutation/image1.png)

Permutation, as defined, is the process of reordering a set of specified objects in all conceivable orders. As the image showed above, we can organize three distinct colors in six ways: RGB, RBG, GRB, GBR, BRG, and BGR.

![6 different Permutation of a set](https://storage.googleapis.com/algodailyrandomassets/curriculum/next-permutation/image2.png)

Let's take another example that the set {1, 2, 3} has six different permutations that are (1, 2, 3), (2, 1, 3), (2, 3, 1), (1, 3, 2), (3, 1, 2), and (3, 2, 1). These are the only conceivable arrangements for this collection of three elements. A mathematical method can determine the number of permutations for n different items. In simple words, the product of all positive numbers smaller than or equivalent to n, often known as n factorial, denotes the number of permutations of n different objects. It is typically written as n! Where n! = n*(n-1)*(n-2)*…*1.

The integer's array's next permutation is the next lexicographically greater permutation of the array's integer. More precisely, the next permutation of the array is the permutation that demonstrates it in the ordered container when all the permutations of the array are ordered in a container following its lexicographical ordering. If such an ordering is not feasible, we should reorganize the array in the lowest order feasible that is ordered in ascending order. The greater permutation is the next lexicographic permutation. For instance, BAC will come after ACB. In some instances, such as BBB or DCBA, the lexicographically next permutation doesn't exist.

We have a different set of questions, such as what to do if the input array is arranged in descending order; in this case, we will first arrange the array in increasing order since no greater permutations would be feasible.

Prompt:

Determine the next permutation of a given integers array nums. It is necessary for the replacement to be placed and to only utilised extra constant memory.

Constraints:

  • 1 <= length of nums <= 100
  • 0 <= nums[i] <= 100

You can see the full challenge with visuals at this link.

Challenges • Asked over 1 year ago by Jake from AlgoDaily

Jake from AlgoDaily Commented on Sep 11, 2022:

This is the main discussion thread generated for Next Permutation (Main Thread).