Pancake Sorting
The problem of pancake sorting is unique because it doesn’t allow us to simply swap two elements; instead, we can reverse an entire prefix of the array.
Here’s a general strategy to sort the array using pancake flips:
Find the Largest Unsorted Element: Find the largest element that is not in its correct position.
Flip to Beginning: Flip the subarray that ends with the largest unsorted element, so that this element comes to the beginning of the array.
Flip to Correct Position: Now that the largest unsorted element is at the beginning of the array, flip the subarray that ends with the correct position for this element. This places the element in its correct position.
Repeat for Remaining Elements: Repeat steps 13 for the remaining unsorted elements.
Here’s the code implementing this approach:


This code returns the sequence of flips required to sort the given array. The flip function is a simple reversal of the first k elements of the given subarray. The main part of the algorithm iteratively finds the largest unsorted element, flips it to the beginning, then flips it to its correct final position.