Problem Given two sorted integer arrays nums1 and nums2, merge nums2 into nums1 as one sorted array. Note: You may assume that nums1 has enough space (size that is greater or equal to m + n) to h...

Problem Given a sorted linked list, delete all duplicates such that each element appear only once. For example, Given 1->1->2, return 1->2. Given 1->1->2->3->3, return 1->...

Problem You are climbing a stair case. It takes n steps to reach to the top. Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top? Note: Given n will b...

Problem Implement int sqrt(int x). Compute and return the square root of x. x is guaranteed to be a non-negative integer. Example 1: Input: 4 Output: 2 Example 2: Input: 8 Output: 2 Explanat...

Problem Given two binary strings, return their sum (also a binary string). For example, a = “11” b = “1” Return “100”. 题目的意思就是按二进制的方式计算两个数相加。 Java 实现 package com.coderli.leetcode.algorithms...

Problem Given a non-negative integer represented as a non-empty array of digits, plus one to the integer. You may assume the integer do not contain any leading zero, except the number 0 itself. ...

Problem Given a string s consists of upper/lower-case alphabets and empty space characters ‘ ‘, return the length of last word in the string. If the last word does not exist, return 0. Note: A w...

Problem Find the contiguous subarray within an array (containing at least one number) which has the largest sum. For example, given the array [-2,1,-3,4,-1,2,1,-5,4], the contiguous subarray [4,-...

Problem The count-and-say sequence is the sequence of integers with the first five terms as following: 1 11 21 1211 111221 1 is read off as “one 1” or 11. 11 is read off as “two 1s” ...

Problem Implement strStr(). Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. 题目其实就是实现Java中String的indexOf函数。因此，直接调用该方法，显然是不合适的。 Java 实现...