easy

Final Value of Variable After Performing Operations

The problem "Final Value of Variable After Performing Operations" involves performing a sequence of operations on a variable x, where each operation is either incrementing or decrementing the value of x by 1, based on the value of a given string operations. The goal is to determine the final value of x after performing all the operations in the given string.

Here is a JavaScript solution to the problem:

function finalValueAfterOperations(operations) {
  let res = 0;
  for (let i = 0; i < operations.length; i++) {
    if (operations[i] === "++X" || operations[i] === "X++") {
      res++;
    } else {
      res--;
    }
  }
  return res;
}

In this solution, we initialize the variable res to 0. We then loop through each character in the string operations. If the current character is either '++X' or 'X++', we increment res by 1. Otherwise, we decrement res by 1.

The time complexity of this solution is O(n), where n is the length of the input string operations, because we are iterating through the string one character at a time. The space complexity of this solution is O(1), because we are only using a single variable to store the value of res.