2015 年 12月 22 日随笔档案 - neverlandly

2015年12月22日

摘要：我的方法：注意最方便的获取一个数每一位的方法，是把它转化为String先，通过String.valueOf(int c) O（1）： http://my.oschina.net/Tsybius2014/blog/497645 另一个方法比较简单，可以举例说明一下。假设输入的数字是一个5位数字num，阅读全文

posted @ 2015-12-22 13:28 neverlandly 阅读(240) 评论(0) 推荐(0)

Leetcode: Binary Tree Paths

摘要： Given a binary tree, return all root-to-leaf paths.For example, given the following binary tree: 1 / \2 3 \ 5All root-to-leaf paths are:["1->... 阅读全文

posted @ 2015-12-22 12:44 neverlandly 阅读(274) 评论(0) 推荐(0)

Leetcode: Verify Preorder Sequence in Binary Search Tree

摘要： 4 / \ 2 6 / \ / \ 1 3 5 7 如图所示BST， preorder结果是 4 2 1 3 6 5 7 4是root, 213是左子树，657是右子树 idea就是右子树不能再出现比root小的数，一旦出现，return false. 这样一层一层recursion, 直到子树只剩阅读全文

posted @ 2015-12-22 11:16 neverlandly 阅读(293) 评论(0) 推荐(0)

Leetcode: Meeting Rooms II

摘要： Like the previous one Meeting Room, still need to sort the intervals using a comparator. We need to simulate the process to know the maximum number of 阅读全文

posted @ 2015-12-22 09:19 neverlandly 阅读(943) 评论(0) 推荐(0)

Leetcode: Meeting Rooms

摘要： Interval as an array: Previous interval as an object: Implement a Comparator<Interval> Syntax: don't forget the public sign when defining a function 阅读全文

posted @ 2015-12-22 08:32 neverlandly 阅读(298) 评论(0) 推荐(0)

Leetcode: Flatten 2D Vector

摘要： Implement an iterator to flatten a 2d vector.For example,Given 2d vector =[ [1,2], [3], [4,5,6]]By calling next repeatedly until hasNext returns fa... 阅读全文

posted @ 2015-12-22 08:13 neverlandly 阅读(278) 评论(0) 推荐(0)

Leetcode: Count Univalue Subtrees

摘要： Given a binary tree, count the number of uni-value subtrees.A Uni-value subtree means all nodes of the subtree have the same value.For example:Given b... 阅读全文

posted @ 2015-12-22 07:22 neverlandly 阅读(1741) 评论(0) 推荐(0)

Leetcode: Group Shifted Strings

摘要： Given a string, we can "shift" each of its letter to its successive letter, for example: "abc" -> "bcd". We can keep "shifting" which forms the sequen... 阅读全文

posted @ 2015-12-22 02:04 neverlandly 阅读(435) 评论(0) 推荐(0)