Insert Delete GetRandom O(1) LeetCode Challenge June Day 12

Quoestion: ClickHere

Solution:

Data Structure We are going to use is Array

1.insert(val):Before inserting check if number is already in array or not.If it is there then return False otherwise add element at end of array and return True

2.remove(val):check if number is already in array or not.If it is present then delete it and return True if it is not present Return False

3.getRandom:Return a Random number from list

Python Code:

import random
class RandomizedSet:

    def __init__(self):
        self.ds = []
        self.indexes = {}

    def insert(self, val: int) -> bool:
        if val not in self.indexes:
            self.ds.append(val)
            self.indexes[val] = len(self.ds)-1 
            return True        
        return False
    def remove(self, val: int) -> bool:
        if val in self.indexes:
            self.ds.remove(val)
            del self.indexes[val]
            return True
        else:
            return False

    def getRandom(self) -> int:
        return random.choice(self.ds).