_735. Asteroid Collision.md

735. Asteroid Collision

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First completed : July 14, 2024

Last updated : July 14, 2024

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Related Topics : Array, Stack, Simulation

Acceptance Rate : 44.72 %

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Very VERY similar to the daily question from yesterday called robot collisions.

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Solutions

• m735.py

Python

m735.py

class Solution:
    def asteroidCollision(self, asteroids: List[int]) -> List[int]:
        output = []
        stk = []

        while asteroids :
            # going right
            if asteroids[-1] > 0 :
                # while current asteroid is larger than the ones going left
                while stk and stk[-1] + asteroids[-1] > 0 :
                    stk.pop()
                
                # if same size
                if stk and stk[-1] == -asteroids[-1] :
                    asteroids.pop()
                    stk.pop()
                # no astroids not destroyed going left
                elif not stk :
                    output.append(asteroids.pop())
                # asteroid going left is larger than current
                else : # smaller
                    asteroids.pop()
            # asteroid going left
            else :
                stk.append(asteroids.pop())

        return stk[::-1] + output[::-1]