pengyu2003

摘要： 今天看到了阿里实习终面通过的消息，非常开心，同时也为天龙感到惋惜。阿里实习的这三面通过，可以说运气还是占了一定成分的，我不大会的东西都没怎么问，问的大都是撞到我的枪口下的，因此比较顺利。如果再来一次，把那些恶心的问题都问我，未必能够走到这一步。这段时间，真的非常感谢天龙和文清，大家有消息第一时间互相通知，有问题互相沟通，一同学习一起讨论算法，无论结果如何，这一阵子是我提升非常快的一段时间。人须有自知之明，如果没有天龙和文清，我是不可能如此顺利走到这一步的。面试阶段暴露了很多问题，基础还需要进一步掌握。如果对待一个问题，不能拿出最佳的算法，这个问题就不算解决。要感谢的人还有很多，我亲爱的高中同学 阅读全文

摘要： There areNgas stations along a circular route, where the amount of gas at stationiisgas[i].You have a car with an unlimited gas tank and it costscost[i]of gas to travel from stationito its next station (i+1). You begin the journey with an empty tank at one of the gas stations.Return the starting gas 阅读全文

摘要： 仔细想想，越来越感觉自己的代码写的烂，不是一般的烂……还是太紧张了，希望能够迅速成长，起码别再这么紧张。两个题：1.链表反转2.#切割字符都是很简单的题。虽然结果问题不大，代码写那么差，实在是太丢人了，对不起实验室，对不起师兄…… 阅读全文

摘要： There areNchildren standing in a line. Each child is assigned a rating value.You are giving candies to these children subjected to the following requirements:Each child must have at least one candy.Children with a higher rating get more candies than their neighbors.What is the minimum candies you mu 阅读全文

摘要： Given an array of integers, every element appearstwiceexcept for one. Find that single one.和上一题比这题就是渣。class Solution {public: int singleNumber(int A[], int n) { if(A == NULL)return 0; int re = 0; for(int i = 0 ; i < n ;i++)re ^= A[i]; return re; }}; 阅读全文

摘要： Given an array of integers, every element appearsthreetimes except for one. Find that single one.Note:Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory?本题最好理解版本有的数字出现3次，个别出现1次，因此每出现3次就可以归零了。我们用三个量分别记录出现1次、2次、3次（其实就是0次）的位，分别为x1,x2,x3.某一位出现1次，可能之 阅读全文

摘要： A linked list is given such that each node contains an additional random pointer which could point to any node in the list or null.Return a deep copy of the list.这题貌似见过，大概是编程之美之类吧。复习一下深拷贝和浅拷贝的区别：深拷贝保存了指针指向的内容，二浅拷贝应对指针指示给指针赋值。所以对于有指针的地方，浅拷贝非常不安全。这段代码用了2个栈，感觉很不效率，空间O(n)。有个空间O（1）的。/** * Definition for 阅读全文

摘要： Given a stringsand a dictionary of wordsdict, determine ifscan be segmented into a space-separated sequence of one or more dictionary words.For example, givens="leetcode",dict=["leet", "code"].Return true because"leetcode"can be segmented as"leet code&quo 阅读全文

摘要： Given a linked list, determine if it has a cycle in it.Follow up:Can you solve it without using extra space?更简单的环题/** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x) : val(x), next(NULL) {} * }; */class Solution {public: bool has... 阅读全文

摘要： Given a linked list, return the node where the cycle begins. If there is no cycle, returnnull.Follow up:Can you solve it without using extra space?老题，没难度。/** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x) : val(x), next(NULL) {} * ... 阅读全文