158k views
0 votes
Describe the process of finding the next greater permutation in lexicographic order.

User Hagar
by
7.5k points

1 Answer

4 votes

Final answer:

The process of finding the next greater permutation in lexicographic order involves identifying the longest non-increasing suffix, locating the pivot, swapping with the successor, and then reversing the suffix. It's a useful method in combinatorics and computer algorithms to generate permutations sequentially.

Step-by-step explanation:

Finding the next greater permutation of a sequence in lexicographic order is a mathematical process that consists of several steps. This process can be applied to various types of data like numbers, letters, or other sortable elements. Here is a step-by-step method to find the next permutation:

  1. Identify the longest non-increasing suffix (the part of the permutation that is in descending order when read from right to left).
  2. Look at the element just before the non-increasing suffix (pivot). Find the smallest element in the suffix that is bigger than the pivot.
  3. Swap the pivot with this successor element.
  4. Reverse the suffix into increasing order. Now you have the next greater permutation in lexicographic order.

For example, given the permutation 1,3,5,4,2:

  • The non-increasing suffix is 5,4,2.
  • The pivot is 3.
  • The successor to the pivot in the suffix is 4.
  • Swap them to get 1,4,5,3,2.
  • Reverse the suffix after pivot to get 1,4,2,3,5, which is the next permutation.

Following these steps, one can generate permutations in a sequential and orderly fashion.

User Jaehong
by
8.2k points