xpp

方法一：不进行夹逼，直接使用类似2Sum的方法，使用一个hashTable，键值对应vector中的数值，value对应vector对用数值的索引，这其中有一个小trick：最外层的循环需要出力重复数字，但是再深一层的循环判断重复数字时需要避开最外层循环的数字，如处理（-1， -1， 2）这种情况 Read More

Implement strStr().Returns a pointer to the first occurrence of needle in haystack, ornullif needle is not part of haystack.思路：时间复杂度O(m*n)，也就是BF（Brute... Read More

Given two binary strings, return their sum (also a binary string).For example,a ="11"b ="1"Return"100".思路简单（同Add Two Numbers），可从代码得知，需要注意字符在字符串中的插入；co... Read More

erase():erase函数的原型如下：（1）string& erase ( size_t pos = 0, size_t n = npos );（2）iterator erase ( iterator position );（3）iterator erase ( iterator first, ... Read More

Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases.//数字或字母For example,"A man, a plan, a cana... Read More

Given a list, rotate the list to the right bykplaces, wherekis non-negative.For example:Given1->2->3->4->5->NULLandk=2,return4->5->1->2->3->NULL.思路：将单... Read More

Given an arraySofnintegers, find three integers inSsuch that the sum is closest to a given number, target. Return the sum of the three integers. You m... Read More

Given an arraySofnintegers, are there elementsa,b,cinSsuch thata+b+c= 0? Find all unique triplets in the array which gives the sum of zero.Note:Elemen... Read More

Given a linked list and a valuex, partition it such that all nodes less thanxcome before nodes greater than or equal tox.You should preserve the origi... Read More

Given a sorted linked list, delete all duplicates such that each element appear onlyonce.For example,Given1->1->2, return1->2.Given1->1->2->3->3, retu... Read More