Given a string, this function returns the first non-repeating character in the string. For example, given the input string "abcab", the function would return "c".
About this solution: The candidate's solution is correct and demonstrates a level of completeness. The solution uses a dictionary to store the number of times each character appears in the string and then iterates through the string to find the first character that appears only once. The solution is optimal because it only iterates through the string once.
The problem is to find the index of a given target value in a sorted array of integers. If the target value is not found in the array, the function should return -1.
About this solution: This solution is optimal because it is O(n) time complexity. However, it is not the most efficient solution. A more efficient solution would be to use a binary search, which would have a time complexity of O(log n).
The "Index of Target Number in List" code problem asks the reader to write a function that takes in a list of integers and a target number, and returns the index of the target number if it is present in the list, or -1 if it is not present.
About this solution: The candidate's solution is correct and uses a linear search algorithm, which is the most efficient way to search for an element in a list. The candidate's solution is complete and solves the problem.
This problem deals with finding a route between two nodes in a directed graph. An example input is given, and the expected output is "There is a route between A and D."
About this solution: The candidate's solution is correct and uses a breadth-first search to find the shortest path between two nodes. The time complexity is O(n) and the space complexity is O(n).
This problem asks to return all possible subsets of a given set of distinct integers. For example, for the input [1,2,3], the output would be all possible subsets of those integers: [1], [2], [3], [1,2], [1,3], [2,3], and [1,2,3].
About this solution: The candidate's solution is correct and solves the problem. The approach is to use a recursive function that takes in a list of integers and a list of lists. The function will iterate through the list of integers and add each integer to the list of lists. Then it will call itself with the list of integers minus the current integer and the list of lists. This will continue until the list of integers is empty. The function will then return the list of lists. This solution is optimal because it is O(2^n) time complexity and O(n) space complexity.
The problem asks us to print the power set of a given set of distinct integers. A power set is the set of all subsets of a given set, including the empty set and the original set itself. For example, the power set of {1,2,3} would be {{},{1},{2},{3},{1,2},{1,3 },{2,3},{1,2,3}}.
About this solution: This is a good solution that demonstrates a level of completeness and solves the problem. The approach is recursive and uses a set and a list to keep track of the elements in the power set.
This technical problem deals with the binary search algorithm, specifically searching for a given key in a sorted array. The function should return the index of the key if it is found, or -1 if it is not found.
About this solution: The candidate's solution correctly implements a binary search algorithm to find the index of a given key in a sorted array. The solution is efficient and correctly returns the index of the key if it is present in the array, or -1 if it is not.
The problem asks for the sum of all elements in an array. An example input is given as [1, 2, 3, 4, 5] and the expected output is 15.
About this solution: The candidate's solution is correct and demonstrates a level of completeness. The candidate has used the built-in sum function, which is an optimal solution.