2015 年 4月随笔档案 - Tonix

HackerRank - AntiPalindromic Strings

摘要：My first reaction was, total No. of strings - no. of palindromic strings. But looks like counting all palindromic strings is not that easy.. So it has... 阅读全文

posted @ 2015-04-30 15:30 Tonix 阅读(240) 评论(0) 推荐(0)

HackerRank - Sherlock and Anagram

摘要：Please note input constraints. String length will not exceed 100, which means, we can use relatively naive representation\calculation for anagrams: so... 阅读全文

posted @ 2015-04-30 13:29 Tonix 阅读(473) 评论(0) 推荐(0)

LeetCode "Count Primes"

摘要：Sieve of Eratosthenesclass Solution {public: int countPrimes(int n) { if(n rec(n + 1, false); int bound = floor(sqrt(n)); i... 阅读全文

posted @ 2015-04-30 01:04 Tonix 阅读(138) 评论(0) 推荐(0)

HackerRank - Count Luck

摘要：Simplied a DFS\BFS with minor modification.#include #include #include #include #include #include using namespace std;typedef vector> Matrix;typedef pa... 阅读全文

posted @ 2015-04-27 14:16 Tonix 阅读(542) 评论(0) 推荐(0)

HackerRank - Cut the Tree

摘要：Typical tree recursion works. The key is: ANY node can be treated as the root, since it is about edge, not about node. This simplifies things a lot.#i... 阅读全文

posted @ 2015-04-27 14:14 Tonix 阅读(233) 评论(0) 推荐(0)

HackerRank - Xoring Ninja

摘要：This is a super interesting bit problem. This link can be found in discussion panel:http://math.stackexchange.com/questions/712487/finding-xor-of-all-... 阅读全文

posted @ 2015-04-23 05:18 Tonix 阅读(432) 评论(0) 推荐(0)

HackerRank - Counter game

摘要：Intuitive coding problem. But several details to take care.#include #include #include #include #include #include #include using namespace std;bool pla... 阅读全文

posted @ 2015-04-20 07:34 Tonix 阅读(205) 评论(0) 推荐(0)

HackerRank - Even Tree

摘要：Typical greedy\recursion algorithm.#include #include #include #include #include #include using namespace std;struct Node{ Node() : pinx(0), nodeCnt... 阅读全文

posted @ 2015-04-17 14:16 Tonix 阅读(322) 评论(0) 推荐(0)

HackerRank - Sansa and XOR

摘要：Really interesting problem! My 1st solution was DP based, like bottom-up pattern, but it got TLE since it is O(n^2). Then I thought there must be a O(... 阅读全文

posted @ 2015-04-16 14:52 Tonix 阅读(393) 评论(0) 推荐(0)

LeetCode "Bitwise AND of Numbers Range"

摘要：Just picture the shifting process in your mind..class Solution {public: int rangeBitwiseAnd(int m, int n) { if (m == n) return m; int... 阅读全文

posted @ 2015-04-16 12:52 Tonix 阅读(117) 评论(0) 推荐(0)

HackerRank - Cipher

摘要：A coding problem. The trick is, some part of computation can be reused from last iteration. Check out my code:#include #include #include #include #inc... 阅读全文

posted @ 2015-04-16 12:30 Tonix 阅读(314) 评论(0) 推荐(0)

HackerRank - The Trigonometric Ratios (Code Golf)

摘要：I tried Python:def f(x,i,n,a,b,r,s,w): if(i>n):return r return f(x,i+1,n,a*x*x,b*2*i*(2*i+s),r+a*w/b,s,-w)n=int(input())for _ in range(n): v=... 阅读全文

posted @ 2015-04-16 10:18 Tonix 阅读(185) 评论(0) 推荐(0)

LeetCode "Binary Tree Right Side View"

摘要：I saw a lot of BFS based solutions. And my alternative solution is this mirror-ed BST iterator one, with some book-keeping:class Solution {public: ... 阅读全文

posted @ 2015-04-13 11:28 Tonix 阅读(167) 评论(0) 推荐(0)

HihoCoder - Floyd算法

摘要：Floyd-Warshall算法其实是比较容易理解也比较容易coding的DP... 不说了，上代码：#include #include #include #include #include #include #include #include #include using namespace st... 阅读全文

posted @ 2015-04-07 13:19 Tonix 阅读(139) 评论(0) 推荐(0)

HihoCoder - 01\完全背包

摘要：HihoCoder上有两道背包问题的problem，http://hihocoder.com/problemset/problem/1038 （01背包）#include #include #include #include #include #include #include using name... 阅读全文

posted @ 2015-04-03 05:05 Tonix 阅读(224) 评论(0) 推荐(0)

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04 2015 档案