This problem is about backtracking, or generating all possible permutations of a given set of distinct integers. For example, if the input is [1,2,3], then the output should be [[1,2,3],[1,3,2],[2,1,3],[2,3,1],[3,1,2],[3,2,1]].

283

Dec 13
This function checks whether a given string containing only '(', ')' and '*' characters is valid. A string is considered valid if it follows the rules defined above.

234

Dec 13
This problem deals with reversing a linked list. The input is a list of nodes, and the output should be the list of nodes in reverse order.

248

Dec 13
Given an array of n integers, where each integer represents the height of a bar in a bar graph, write a function that returns the maximum area that can be formed by choosing two bars from the array and stacking them on top of each other.

293

Dec 13
This problem asks us to return all possible subsets of a given set of distinct integers. For example, if the input is [1,2,3], then the output should be all possible subsets of those integers: [1], [1,2], [1,2,3], [1,3], [2], [2,3], and [3].

284

Dec 12
This problem asks us to develop an algorithm that can determine whether or not a given string has all unique characters. For example, the input string "abcdefg" would return True, while the input string "aabbcc" would return False.

257

Dec 12
This technical problem asks the coder to return the sum of the elements in an array. The input is an array of integers and the output should be the sum of those integers.

263

Dec 12
To find the deepest node in a binary tree, we can use recursion. We can keep track of the maximum depth as we traverse the tree, and return the deepest node's value when we reach the end of the tree.

201

Dec 12