LeetCode-in-Java

2011. Final Value of Variable After Performing Operations

Easy

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.

Example 2:

Input: operations = [”++X”,”++X”,”X++”]

Output: 3

Explanation: The operations are performed as follows:

Initially, X = 0.

++X: X is incremented by 1, X = 0 + 1 = 1.

++X: X is incremented by 1, X = 1 + 1 = 2.

X++: X is incremented by 1, X = 2 + 1 = 3.

Example 3:

Input: operations = [“X++”,”++X”,”–X”,”X–”]

Output: 0

Explanation: The operations are performed as follows:

Initially, X = 0.

X++: X is incremented by 1, X = 0 + 1 = 1.

++X: X is incremented by 1, X = 1 + 1 = 2.

–X: X is decremented by 1, X = 2 - 1 = 1.

X–: X is decremented by 1, X = 1 - 1 = 0.

Constraints:

• 1 <= operations.length <= 100
• operations[i] will be either "++X", "X++", "--X", or "X--".

Solution

public class Solution {
    public int finalValueAfterOperations(String[] operations) {
        int xValue = 0;
        for (String word : operations) {
            if (word.contains("+")) {
                xValue++;
            } else {
                xValue--;
            }
        }
        return xValue;
    }
}

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