Final Value of Variable After Performing Operations

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Question

Approach

I start with X = 0. Each operation either increments (++X or X++) or decrements (--X or X--) the value of X by 1. So, I just iterate through the operations, adding 1 for "++" and subtracting 1 for "--".

Implementation

class Solution:
    def finalValueAfterOperations(self, operations: List[str]) -> int:
        X = 0
        for op in operations:
            if '+' in op:
                X += 1
            else:
                X -= 1
        return X

Complexities

• Time: O(n)
• Space: O(1)