Leetcode - 随笔分类(第13页) - neverlandly

Leetcode: Reconstruct Original Digits from English

摘要：# of '0': # of 'z' # of '2': # of 'w' 4: u 6: x 8: g 3: h - 8 5: f - 4 7: s - 6 1: o - 0 - 2 - 4 9: i - 5 - 6 - 8 我的code用了一个数组来存char count 阅读全文

posted @ 2016-12-05 08:51 neverlandly 阅读(361) 评论(0) 推荐(0)

Leetcode: Maximum XOR of Two Numbers in an Array

摘要：Solution 1: Bit Manipulation: 这题真心有点难，get the max XOR bit by bit note that if A^B=C, then A^C=B, B^C=A Solution 2: Trie, (未研究) https://discuss.leetcod 阅读全文

posted @ 2016-12-05 07:48 neverlandly 阅读(549) 评论(0) 推荐(0)

Leetcode: Battleships in a Board

摘要：只计算每个battleship的第一个元素，所以后面‘X’如果above或者left也是'X'的话，不被计算阅读全文

posted @ 2016-12-05 06:10 neverlandly 阅读(428) 评论(0) 推荐(0)

Leetcode: Split Array Largest Sum

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posted @ 2016-12-05 04:44 neverlandly 阅读(546) 评论(0) 推荐(0)

Leetcode: Find All Anagrams in a String

摘要：Time Complexity will be O(n) because the "start" and "end" points will only move from left to right once. Sliding Window: Use a count to denote the di 阅读全文

posted @ 2016-12-03 13:14 neverlandly 阅读(1400) 评论(0) 推荐(0)

Leetcode: Pacific Atlantic Water Flow

摘要：这题考点在于需要设置两个visited数组 Two Queue and add all the Pacific border to one queue; Atlantic border to another queue. Keep a visited matrix for each queue. I 阅读全文

posted @ 2016-12-03 12:05 neverlandly 阅读(796) 评论(0) 推荐(0)

Leetcode: Partition Equal Subset Sum

摘要：Backpack problem: dp[i][j] means if the first i elements can sum up to value j dp[i][j] = dp[i-1][j] || (j>=nums[i-1] && dp[i-1][j-nums[i-1]]) the res 阅读全文

posted @ 2016-12-03 10:29 neverlandly 阅读(306) 评论(0) 推荐(0)

Leetcode: Third Maximum Number

摘要：My Solution: Highest votes in discussion 阅读全文

posted @ 2016-12-03 06:22 neverlandly 阅读(372) 评论(0) 推荐(0)

Leetcode: Arithmetic Slices

摘要：A slice (P, Q)其实就是从P到Q的序列，（P，Q）是arithmetic slice要求是等差数列且至少有三个数，问array里面有多少个这样的（P, Q）这道题难点在于想到用DP，一旦想到用DP，就迎刃而解 dp[i]表示以i结束的slice有多少个阅读全文

posted @ 2016-12-03 05:12 neverlandly 阅读(368) 评论(0) 推荐(0)

Leetcode: Trapping Rain Water II

摘要：The above image represents the elevation map [[1,4,3,1,3,2],[3,2,1,3,2,4],[2,3,3,2,3,1]] before the rain. After the rain, water are trapped between th 阅读全文

posted @ 2016-12-03 03:16 neverlandly 阅读(554) 评论(0) 推荐(0)

Leetcode: Remove K Digits

摘要：Greedy + Stack: 用一个栈维护最后要留存下来的digits 需要注意的是：如果遍历到string的某个char, string后面的char数刚刚好能填满这个栈，那么即使这个char比栈顶还要小，也不出栈，直接入栈最后要删除leading 0 用char[]实现栈，思路一样，要快很多阅读全文

posted @ 2016-12-03 00:24 neverlandly 阅读(437) 评论(0) 推荐(0)

Leetcode: Add Strings

摘要：Given two non-negative numbers num1 and num2 represented as string, return the sum of num1 and num2. Note: The length of both num1 and num2 is =0 || j>=0 || carry!=0) { 8 int sum = 0; ... 阅读全文

posted @ 2016-12-02 12:46 neverlandly 阅读(318) 评论(0) 推荐(0)

Leetcode: Longest Palindrome

摘要：Given a string which consists of lowercase or uppercase letters, find the length of the longest palindromes that can be built with those letters. This is case sensitive, for example "Aa" is not cons... 阅读全文

posted @ 2016-12-02 12:26 neverlandly 阅读(250) 评论(0) 推荐(0)

Leetcode: Queue Reconstruction by Height

摘要：refer to: https://discuss.leetcode.com/topic/60394/easy-concept-with-python-c-java-solution E.g.input: [[7,0], [4,4], [7,1], [5,0], [6,1], [5,2]]subar 阅读全文

posted @ 2016-12-02 11:58 neverlandly 阅读(368) 评论(0) 推荐(0)

Leetcode: Convert a Number to Hexadecimal

摘要：记住要delete begining 0 要记住单独处理 num == 0的情况阅读全文

posted @ 2016-12-02 11:06 neverlandly 阅读(406) 评论(0) 推荐(0)

Leetcode: Frog Jump

摘要：Solution 1: Backtracking, but will TLE Better Solution: DP (refer to https://discuss.leetcode.com/topic/59903/very-easy-to-understand-java-solution-wi 阅读全文

posted @ 2016-12-02 08:35 neverlandly 阅读(770) 评论(0) 推荐(0)

Leetcode: Binary Watch

摘要：Solution 1: Bit Manipulation use Integer.bitCount() Solution 2: Backtracking, 非常精妙之处在于用了两个数组来帮助generate digit（例如：1011 -> 11）阅读全文

posted @ 2016-12-02 05:00 neverlandly 阅读(241) 评论(0) 推荐(0)

Leetcode: Evaluate Division

摘要：Graph, DFS (1) Build the map, the key is dividend, the value is also a map whose key is divisor and value is its parameter. For example, a / b = 2.0, 阅读全文

posted @ 2016-12-02 02:10 neverlandly 阅读(327) 评论(0) 推荐(0)

Leetcode: Fizz Buzz

摘要：Solution 1: Solution with out using % 阅读全文

posted @ 2016-12-01 12:46 neverlandly 阅读(418) 评论(0) 推荐(0)

Leetcode: Integer Replacement

摘要：Refer to: https://discuss.leetcode.com/topic/58334/a-couple-of-java-solutions-with-explanations/2 When to add 1 instead of minus 1, here is an example 阅读全文

posted @ 2016-12-01 12:31 neverlandly 阅读(363) 评论(0) 推荐(0)

随笔分类 - Leetcode