sharonITlion的博客

给定一个整数数组 nums 和一个目标值 target，请你在该数组中找出和为目标值的那 两个 整数，并返回他们的数组下标。你可以假设每种输入只会对应一个答案。但是，你不能重复利用这个数组中同样的元素。示例:给定 nums = [2, 7, 11, 15], target = 9因为 nums[0] + nums[1] = 2 + 7 = 9 所以返回 [0, 1]解题方法：cla...

题目：Write a program to find the node at which the intersection of two singly linked lists begins.For example, the following two linked lists:A: a1 → a2 ↘

题目：Given an array of integers, every element appears twice except for one. Find that single one.Note:Your algorithm should have a linear runtime complexity. Could you implement it with

题目：Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases.For example,"A man, a plan, a canal: Panama" is a palindrome."race a car" is

题目：Say you have an array for which the ith element is the price of a given stock on day i.Design an algorithm to find the maximum profit. You may complete as many transactions as you like (ie,

题目：Say you have an array for which the ith element is the price of a given stock on day i.If you were only permitted to complete at most one transaction (ie, buy one and sell one share o

题目：Given an index k, return the kth row of the Pascal's triangle.For example, given k = 3,Return [1,3,3,1].Note:Could you optimize your algorithm to use only O(k) extra space?代码：

题目：Given numRows, generate the first numRows of Pascal's triangle.For example, given numRows = 5,Return[ [1], [1,1], [1,2,1], [1,3,3,1], [1,4,6,4,1]]da代码＋调试：clas

题目：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 be a

题目：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: 4Output: 2Example 2:Input: 8Output: 2Explan

题目：Given two binary strings, return their sum (also a binary string).For example,a = "11"b = "1"Return "100".代码＋调试：class Solution(object): def addBinary(self, a

题目：Given a linked list, determine if it has a cycle in it.Follow up:Can you solve it without using extra space?解释：判断链表是否有环，如果可以用额外空间，可以使用字典记录键的次数，大于1则存在环。现有情况下可以用快慢指针方法，慢指针走一步，

题目：Design a stack that supports push, pop, top, and retrieving the minimum element in constant time.push(x) -- Push element x onto stack.pop() -- Removes the element on top of the stack.top(

Write a function that takes an unsigned integer and returns the number of ’1' bits it has (also known as the Hamming weight).For example, the 32-bit integer ’11' has binary representation 000000000000...

Reverse bits of a given 32 bits unsigned integer.For example, given input 43261596 (represented in binary as 00000010100101000001111010011100), return 964176192 (represented in binary as 0011100101111...

题目：Rotate an array of n elements to the right by k steps.For example, with n = 7 and k = 3, the array [1,2,3,4,5,6,7] is rotated to [5,6,7,1,2,3,4].Note:Try to come up as many solutions as you can, th...

题目：Table: Person+-------------+---------+| Column Name | Type |+-------------+---------+| PersonId | int || FirstName | varchar || LastName | varchar |+-------------+---------+Pe...

题目：Given an integer n, return the number of trailing zeroes in n!.Note: Your solution should be in logarithmic time complexity.解释：求阶乘后0的个数，如果使用暴力可能会超出范围，而且速度会很慢。分析题目特点0的个数，即n!有多少个10，10又可以分解为2*5，2很充足，就...

题目：Related to question Excel Sheet Column TitleGiven a column title as appear in an Excel sheet, return its corresponding column number.For example: A -> 1 B -> 2 C -> 3

题目：Given an array of size n, find the majority element. The majority element is the element that appears more than ⌊ n/2 ⌋ times.You may assume that the array is non-empty and the majority e

题目：Given a positive integer, return its corresponding column title as appear in an Excel sheet.For example: 1 -> A 2 -> B 3 -> C ... 26 -> Z 27 -> AA 28 -> AB

题目：Given an array of integers that is already sorted in ascending order, find two numbers such that they add up to a specific target number.The function twoSum should return indices of the two

题目：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.The

题目：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 wo

题目：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,-

Write a function to find the longest common prefix string amongst an array of strings.class Solution(object): def longestCommonPrefix(self, strs): """ :type strs: List[str]

题目：Given a binary tree, find its maximum depth.The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.For example:Given binary tr

题目：Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center).For example, this binary tree [1,2,2,3,4,4,3] is symmetric: 1 / \ 2 2 / \ / \3

题目：Given two binary trees, write a function to check if they are the same or not.Two binary trees are considered the same if they are structurally identical and the nodes have the same value.

题目：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 hol

Given a roman numeral, convert it to an integer.Input is guaranteed to be within the range from 1 to 3999.这里说一下罗马数的简单规则，左边的数>右边的数时，两个数相加，左边的数"DCXXI" ＝ 621romanToint = {'I':1,'V':5,

题目：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->2->3.代码＋调试：class Li

Determine whether an integer is a palindrome. Do this without extra space.Some hints:Could negative integers be palindromes? (ie, -1)If you are thinking of converting the integer to stri

题目：Given a 32-bit signed integer, reverse digits of an integer.Example 1:Input: 123Output: 321Example 2:Input: -123Output: -321Example 3:Input: 120Output: 21

题目：Given a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.The brackets must close in the correct order, "()" and "()[]{}" are

题目：Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists.Example:Input: 1->2->4, 1->3->4Output: 1->1->

题目：Given a binary tree, return the bottom-up level order traversal of its nodes' values. (ie, from left to right, level by level from leaf to root).For example:Given binary tree [3,9,20,null

题目：The count-and-say sequence is the sequence of integers with the first five terms as following:1. 12. 113. 214. 12115. 1112211 is read off as "one 1" or 11.11 

题目：Implement strStr().Return the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.Example 1:Input: haystack = "hello", needle = "ll"Output: 2

题目：Given a sorted array and a target value, return the index if the target is found. If not, return the index where it would be if it were inserted in order.You may assume no duplicates in the