This topic has been in my wish list for a long time. I will try to articulate my understanding of eigenvector and eigenvalue after digestion informative materials from different sources. First of all, we can consider multiplication between a square matrix and a vector as a transformation of such that is rotated and scaled. By …
Continue reading “How to understand Eigenvector/Eigenvalue?”
https://leetcode.com/problems/minimum-depth-of-binary-tree/ Given a binary tree, find its minimum depth. The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node. Code # Definition for a binary tree node. # class TreeNode(object): # def __init__(self, x): # self.val = x # self.left = None …
Continue reading “Leetcode 111: Minimum Depth of Binary Tree”
https://leetcode.com/problems/largest-number/ Given a list of non negative integers, arrange them such that they form the largest number. For example, given [3, 30, 34, 5, 9], the largest formed number is 9534330. Note: The result may be very large, so you need to return a string instead of an integer. Code class Solution(object): def largestNumber(self, …
https://leetcode.com/problems/path-sum-ii/ Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum. For example: Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ \ …
https://leetcode.com/problems/path-sum-ii/ Given a binary tree and a sum, find all root-to-leaf paths where each path’s sum equals the given sum. For example: Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ / \ 7 2 5 1 return [ [5,4,11,2], [5,8,4,5] ] …
https://leetcode.com/problems/valid-anagram/ Given two strings s and t, write a function to determine if t is an anagram of s. For example,s = “anagram”, t = “nagaram”, return true.s = “rat”, t = “car”, return false. Note:You may assume the string contains only lowercase alphabets. Follow up:What if the inputs contain unicode characters? How would you …
https://leetcode.com/problems/distinct-subsequences/ Given a string S and a string T, count the number of distinct subsequences of T in S. 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 remaining characters. (ie, "ACE" …
I used to create 2D zero array by the following way, for example: arr = [[0] * 3] * 4 However, `arr` actually references the list [0,0,0] 4 times. If you set `arr[1][1] = 5`, for example, you will find all “other” lists in `arr` have 5 then. >>> arr[1][1] = 5 >>> arr [[0, …
https://leetcode.com/problems/valid-number/ 65. Valid Number Total Accepted: 38767 Total Submissions: 328141 Difficulty: Hard Validate if a given string is numeric. Some examples:"0" => true" 0.1 " => true"abc" => false"1 a" => false"2e10" => true Note: It is intended for the problem statement to be ambiguous. You should gather all requirements up front before implementing one. …
1.Use a specified port (e.g., 12345) for SSH SOCKS server: ssh -D 12345 user@host.domain 2. Go to the setting menu in Firefox, then Advanced->Network->Connection->Settings 3.Check the “Manual proxy configuration”, fill in SOCKS host (127.0.0.1) and port (your specified port, 12345 in our example) 4. Also, type in “about:config” in the address bar in Firefox, change …