[LeetCode]#2011. Final Value of Variable After Performing Operations

Environment: Python 3.8

Key technique: for, if

There is a programming language with only four operations and one variable X:

• ++X and X++ increments the value of the variable X by 1.
• --X and X-- decrements the value of the variable X by 1.

Initially, the value of X is 0.

Given an array of strings operations containing a list of operations, return the final value of X after performing all the operations.

Example 1:

Input: operations = ["--X","X++","X++"]
Output: 1
Explanation: The operations are performed as follows:
Initially, X = 0.
--X: X is decremented by 1, X =  0 - 1 = -1.
X++: X is incremented by 1, X = -1 + 1 =  0.
X++: X is incremented by 1, X =  0 + 1 =  1.

Analysis:

Solution:

class Solution:
    def finalValueAfterOperations(self, operations):
        ans=0
        for i in operations:
            if (i=="X++" or i=="++X"):
                ans=ans+1
            else:
                ans=ans-1
        return ans

Submissions: