题目 //像10进制一样进行 转换   只是要从0开始记录 class Solution { public: string convertToTitle(int n) { char a; string str=""; ){ )%; str = char(tmp+'A') + str; n = (n-)/; } return str; } }; 171  Excel Sheet Column Number class Solution { public: int titleToNumbe…

class Solution { public: string convertToTitle(int n) { ) { return ""; } ) / ) + () % + 'A'); } }; A -> 1 B -> 2 C -> 3 ... Z -> 26 AA -> 27 AB -> 28 答案写法: class Solution { public: int titleToNumber(string s) { ; ; ; i < s.l…

28. Search a 2D Matrix [easy] Write an efficient algorithm that searches for a value in an mx n matrix. This matrix has the following properties: Integers in each row are sorted from left to right. The first integer of each row is greater than the la…

170. Two Sum III - Data structure design[easy] Design and implement a TwoSum class. It should support the following operations:add and find. add - Add the number to an internal data structure.find - Find if there exists any pair of numbers which sum…

160. Intersection of Two Linked Lists[easy] 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 ↘ c1 → c2 → c3 ↗ B: b1 → b2 → b3 begin to intersect at n…

206. Reverse Linked List[easy] Reverse a singly linked list. Hint: A linked list can be reversed either iteratively or recursively. Could you implement both? 解法一: class Solution { public: ListNode* reverseList(ListNode* head) { ListNode * pre = NULL;…

203. Remove Linked List Elements[easy] Remove all elements from a linked list of integers that have value val. ExampleGiven: 1 --> 2 --> 6 --> 3 --> 4 --> 5 --> 6, val = 6Return: 1 --> 2 --> 3 --> 4 --> 5 Credits:Special than…

83. Remove Duplicates from Sorted List[easy] 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. 解法一: /** * Defin…

21. Merge Two Sorted Lists[easy] 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. 解法一: /** * Definition for singly-linked list. * struct ListNode { * int val…

142. Linked List Cycle II[easy] Given a linked list, return the node where the cycle begins. If there is no cycle, return null. Note: Do not modify the linked list. Follow up:Can you solve it without using extra space? 解法一: /** * Definition for singl…