题目如下： Write a program to find the n-th ugly number. Ugly numbers are positive numbers whose prime factors only include 2, 3, 5. Example: Input: n = 10 Output: 12 Explanation: 1, 2, 3, 4, 5, 6, 8, 9, 1… 阅读全文

题目如下： Write a program to check whether a given number is an ugly number. Ugly numbers are positive numbers whose prime factors only include 2, 3, 5. Example 1: Input: 6 Output: true Explanation: 6 = 2… 阅读全文

题目如下： You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed. All houses at this place are arranged in a circle. That means the first hou… 阅读全文

题目如下： You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed, the only constraint stopping you from robbing each of them is that adjacent… 阅读全文

题目如下： Given a non-empty string s and a dictionary wordDict containing a list of non-empty words, add spaces in s to construct a sentence where each word is a valid dictionary word. Return all such pos… 阅读全文

题目如下： Given a non-empty string s and a dictionary wordDict containing a list of non-empty words, determine if s can be segmented into a space-separated sequence of one or more dictionary words. Exampl… 阅读全文

题目如下： Given an integer n, generate all structurally unique BST's (binary search trees) that store values 1 … n. Example: Input: 3 Output: [ [1,null,3,2], [3,2,null,1], [3… 阅读全文

题目如下： Given n, how many structurally unique BST's (binary search trees) that store values 1 … n? Example: Input: 3 Output: 5 Explanation: Given n = 3, there are a total of 5 unique BST's: 1 … 阅读全文