ethan0905 / push_swap

Effective Sort algorithm that get max grade at 42 school

push_swap 🧮

🤏 Pitch

You're gonna need to sort a random list of numbers, using two stacks and with the less amount of moves. To do so, you're gonna manipulate the stacks using only allowed movements: swap (sa, sb, ss), rotate (ra, rb, rr), reverse (rra, rrb, rrr) and push (pa, pb)

Read more here

📔 Summary

• 📺 Preview
• 📈 Performance
• 🧮 Algorithm: Intelligent Insertion Sort
• 👣 Step-by-step to implement your own IIS
• ⚙️ How to run the project ?

📺 Preview

push_swap.70nb.mov

📈 Performances

	Required for 5/5	Mine
For 5 numbers:	< 12 moves	5-11 moves
For 100 numbers:	< 700 moves	500-670 moves
For 500 numbers:	< 5500 moves	4300-4900 moves

🧮 Algorithm made: Intelligent Insertion sort

Goal in this project is to create an algorithm that can sort the list with the less amount of moves.

There is tons of sorting algorithms, but we want to work on one that gonna be enought efficient, and not to hard to develop. That why i created my own algorithm, that think by himself, and take good and the best optimized decision each round.

Everytime my algo need to select one number to sort, it calculate on all remaining numbers which one can be placed at the right place, in the less amount of moves. It takes it, and place it. Then, we iterating until there stack B is empty. We end up with fully sorted stack A.

👣 Step-by-step instructions to follow, for implementation of my IIS algorithm:

1. Push all number from the stack A to the stack B. If that number is < to the median number of the final stack, push it to B (pb) then rotate it in order to make it goes under the stack (rb). Else, if that number is > to the median, simply push it to B (pb). This way, we have a pre-sorted stack on B, with 2 blocks of numbers, the big ones and the small ones.
2. Check the first number of stack B (stackB[0]) and count how much moves you gonna need in order to push it on right spot in A. Then check how much moves you need to push the stackB[1] in on the right spot in A, and so on... When you did this on all stackB, push to A only the one that needed the less amount of moves.
3. Repeat the operation till there is no more number in B.
4. Your stack A is fully sorted, your algo is strong, you can now drop a star on this repo ;)

⚙️ How to run the project ?

1. Clone the repository:
   git clone https://github.com/ethan0905/push_swap.git
2. Compile the project:
   make -j
3. Run the program:
   ./push_swap 3 9 2 5 4 1 8 6 -> if you want to get all instructions
   ./push_swap 3 9 2 5 4 1 8 6 | wc -l -> if you want to get number of instructions
4. Enjoy ;)