C++ Two Sum Solution Using Hashing

The given code is a C++ implementation of the two sum problem using the hashing technique. \n\nThe function `twoSum` takes in a vector of integers `nums` and an integer `target` as input and returns a vector of integers representing the indices of the two numbers that add up to the target. If no such pair is found, an empty vector is returned.\n\nThe function uses an unordered_map `hashtable` to store the elements of `nums` as keys and their corresponding indices as values. \n\nIt then iterates over each element in `nums` using a for loop and checks if the complement of the current element (i.e., `target - nums[i]`) is present in the hashtable. If it is found, the function returns a vector containing the indices of the current element and its complement.\n\nIf the complement is not found in the hashtable, the current element is added to the hashtable with its index as the value.\n\nIf no pair is found after iterating through the entire vector, an empty vector is returned.\n\nThere is a syntax error in the code on line 18. The semicolon after the closing brace of the function should be removed.