2015 年 1月随笔档案 - xgcode

N-Queens II

摘要：class Solution {public: vector hor; vector ver; vector rightline; vector leftline; int len; int result; int totalNQueens(int n) { result ... 阅读全文

posted @ 2015-01-17 14:19 xgcode 阅读(111) 评论(0) 推荐(0)

N-Queens

摘要：题目的要点是：怎么快速判断这次的皇后和以前的是不冲突的。class Solution {public: vector hor; vector ver; vector rightline; vector leftline; int len; vector> result; vector >... 阅读全文

posted @ 2015-01-17 13:48 xgcode 阅读(129) 评论(0) 推荐(0)

Letter Combinations of a Phone Number

摘要：class Solution {public: vector result; vector letterCombinations(string digits) { string buf[] = { "abc","def","ghi","jkl","mno","pqrs","tuv... 阅读全文

posted @ 2015-01-17 10:45 xgcode 阅读(89) 评论(0) 推荐(0)

Combinations

摘要：class Solution {public: vector> result; vector temp; vector > combine(int n, int k) { temp.resize(k); GetCombine(n,k); return result; } ... 阅读全文

posted @ 2015-01-17 10:09 xgcode 阅读(124) 评论(0) 推荐(0)

Longest Valid Parentheses

摘要：难点1，是栈，2是流程class Solution {public: int longestValidParentheses(string s) { stack mstack; char cbefore; int count = 0; if(s.empt... 阅读全文

posted @ 2015-01-11 11:39 xgcode 阅读(102) 评论(0) 推荐(0)

Pow(x, n)

摘要：这道题关键点class Solution {public: double pow(double x, int n) { double result =1; int index = abs(n); for(int i=0; i 0) { ... 阅读全文

posted @ 2015-01-09 21:15 xgcode 阅读(105) 评论(0) 推荐(0)

Intersection of Two Linked Lists

摘要：该题目对内存的使用极其变态。所用变量不能超过4个。否侧会内存超限。解法有两个，其中第二种解法，内存还需要优化，否则会内存越界。解法一：class Solution {public: ListNode *getIntersectionNode(ListNode *headA, ListNode ... 阅读全文

posted @ 2015-01-08 21:36 xgcode 阅读(98) 评论(0) 推荐(0)

String to Integer (atoi)

摘要：这道题知道了用long long 这种变量类型，从最初的128ms优化到68ms代码如下：class Solution {public: int atoi(const char *str) { if(str == NULL) return 0; int i=0; int f... 阅读全文

posted @ 2015-01-01 19:13 xgcode 阅读(149) 评论(0) 推荐(0)

Search for a Range

摘要：这道题没什么好说的，二分法查找class Solution {public: vector range; vector searchRange(int A[], int n, int target) { range.push_back(-1); range.push_b... 阅读全文

posted @ 2015-01-01 16:43 xgcode 阅读(100) 评论(0) 推荐(0)

Word Ladder II

摘要：这道题做了好长时间都没通过，参考了http://blog.csdn.net/niaokedaoren/article/details/8884938的实现，其中在求前驱单词记录时，申请的数组要采用vector>这样，在判断是否结束时，查找效率更高，否则用前向单词记录表查找时效率会很低。算法中的递归找... 阅读全文

posted @ 2015-01-01 13:52 xgcode 阅读(162) 评论(0) 推荐(0)