// A permutation of an array of integers is an arrangement of its members into a sequence or linear order. // For example, for arr = [1,2,3], the following are considered permutations of arr: [1,2,3], ...

Given an array like nums = [1, 2, 3], the next permutation is [1, 3, 2]. If it's the last permutation like [3, 2, 1], then the next should be the smallest one: [1, 2, 3]. Steps: 1.Find the first index ...