English
2011. Final Value of Variable After Performing Operations 
Problem Statement
There is a programming language with only four operations and one variable X:
++XandX++increments the value of the variableXby1.--XandX--decrements the value of the variableXby1.
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 <= 100operations[i]will be either"++X","X++","--X", or"X--".
Click to open Hints
- There are only two operations to keep track of.
- Use a variable to store the value after each operation.
Solution:
rs
impl Solution {
pub fn final_value_after_operations(operations: Vec<String>) -> i32 {
let mut x = 0;
for op in operations {
if op == "--X" || op == "X--" {
x -= 1;
} else {
x += 1;
}
}
x
// operations
// .iter()
// .fold(0, |acc, op| acc + (44 - op.as_bytes()[1] as i32))
}
}
...