摘要： String to Integer (atoi)2014.2.10 02:23Implementatoito convert a string to an integer.Hint:Carefully consider all possible input cases. If you want a challenge, please do not see below and ask yourself what are the possible input cases.Notes:It is intended for this problem to be specified vaguely (i 阅读全文

摘要： Longest Palindromic Substring2014.2.10 00:57Given a stringS, find the longest palindromic substring inS. You may assume that the maximum length ofSis 1000, and there exists one unique longest palindromic substring.Solution1: My first solution to this problem is the brute-force version, with O(n^2) . 阅读全文

摘要： Permutation Sequence2014.2.9 01:00The set[1,2,3,…,n]contains a total ofn! unique permutations.By listing and labeling all of the permutations in order,We get the following sequence (ie, forn= 3):"123""132""213""231""312""321"Givennandk, ret 阅读全文

摘要： First Missing Positive2014.2.8 23:43Given an unsorted integer array, find the first missing positive integer.For example,Given[1,2,0]return3,and[3,4,-1,1]return2.Your algorithm should run inO(n) time and uses constant space.Solution1: The first solution I thought of was hashing, using unordered_map. 阅读全文

摘要： Distinct Subsequences2014.2.8 22:11Given a stringSand a stringT, count the number of distinct subsequences ofTinS.A subsequence of a string is a new string which is formed from the original string by deleting some (can be none) of the characters without disturbing the relative positions of the remai 阅读全文

摘要： Container With Most Water2014.2.8 21:37Givennnon-negative integersa1,a2, ...,an, where each represents a point at coordinate (i,ai).nvertical lines are drawn such that the two endpoints of lineiis at (i,ai) and (i, 0). Find two lines, which together with x-axis forms a container, such that the conta 阅读全文

摘要： 4Sum2014.2.8 20:58Given an arraySofnintegers, are there elementsa,b,c, anddinSsuch thata+b+c+d= target? Find all unique quadruplets in the array which gives the sum of target.Note:Elements in a quadruplet (a,b,c,d) must be in non-descending order. (ie,a≤b≤c≤d)The solution set must not contain duplic 阅读全文

摘要： 剑指Offer - 九度1524 - 复杂链表的复制2014-02-07 01:30题目描述：输入一个复杂链表（每个节点中有节点值，以及两个指针，一个指向下一个节点，另一个特殊指针指向任意一个节点）。输入：输入可能包含多个测试样例，输入以EOF结束。对于每个测试案例，输入的第一行为一个整数n (1 4 #include 5 using namespace std; 6 7 struct RandomListNode { 8 int label; 9 RandomListNode *next, *random; 10 RandomListNode(int ... 阅读全文

摘要： 剑指Offer - 九度1509 - 树中两个结点的最低公共祖先2014-02-07 01:04题目描述：给定一棵树，同时给出树中的两个结点，求它们的最低公共祖先。输入：输入可能包含多个测试样例。对于每个测试案例，输入的第一行为一个数n(0 7 #include 8 using namespace std; 9 10 const int MAXN = 10005; 11 // tree[x][0]: parent of node x 12 // tree[x][1]: left child of node x 13 // tree[x][2]: right child of node... 阅读全文

摘要： 剑指Offer - 九度1508 - 把字符串转换成整数2014-02-06 23:46题目描述：将一个字符串转换成一个整数，要求不能使用字符串转换整数的库函数。输入：输入可能包含多个测试样例。对于每个测试案例，输入为一个合法或者非法的字符串，代表一个整数n(1 4 #include 5 #include 6 using namespace std; 7 8 int main() 9 {10 int i;11 char s[100];12 int len;13 long long int n;14 int flag;15 bool suc;... 阅读全文