摘要： Given a sorted linked list, delete all duplicates such that each element appear only once. Example 1: Example 2: 方法二：直接前向传播 递归是从后往 前找，这个用while循环从前从后找。 阅读全文

摘要： Write a program to find the node at which the intersection of two singly linked lists begins. For example, the following two linked lists: begin to in 阅读全文

摘要： Given a positive integer n, find the least number of perfect square numbers (for example, 1, 4, 9, 16, ...) which sum to n. Example 1: Example 2: 时间复杂 阅读全文

摘要： Java在java.math包中提供的API类BigDecimal，用来对超过16位有效位的数进行精确的运算。双精度浮点型变量double可以处理16位有效数。在实际应用中，需要对更大或者更小的数进行运算和处理。float和double只能用来做科学计算或者是工程计算，在商业计算中要用java.ma 阅读全文

摘要： Given a positive integer n, break it into the sum of at least two positive integers and maximize the product of those integers. Return the maximum pro 阅读全文

摘要： A sequence of number is called arithmetic if it consists of at least three elements and if the difference between any two consecutive elements is the 阅读全文

摘要： Given an integer array nums, find the sum of the elements between indices i and j (i ≤ j), inclusive. Example: Note: 求区间 i ~ j 的和，可以转换为 sum[j + 1] - s 阅读全文

摘要： A robot is located at the top-left corner of a m x n grid (marked 'Start' in the diagram below). The robot can only move either down or right at any p 阅读全文

摘要： Given a linked list, rotate the list to the right by k places, where k is non-negative. Example 1: Example 2: 阅读全文

摘要： Given a m x n grid filled with non-negative numbers, find a path from top left to bottom right which minimizes the sum of all numbers along its path. 阅读全文