Problem Given K and two sorted arrays with length M and N, find the K-th smallest element among all elements in the two arrays. Code import sys class Solution(object): def findKthSmallest(self, nums1, nums2, k): “”” :type nums1: sorted List[int] :type nusm2: sorted List[int] :type k: int :rtype: int “”” if not (0 <k <= …
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Claim In this post, I am using the same notation as in the video below and the wiki page (https://en.wikipedia.org/wiki/Held%E2%80%93Karp_algorithm) Our problem is given a matrix costs in which costs[i][j] is the traveling cost going from node i to node j, we are asked to return the minimum cost for traveling from node 0 and visit …
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Just recap the basic idea of heapsort (return an ascending order): first you build max heap right on the original array. You don’t need to create an additional O(N) space. Instead, just make sure child node index i is always less than parent node (i – 1)/2 by necessary swaps between index i and index (i-1)/2. …
Recently, an exploding reproducibility research paper [1] shows that more than half of past published papers in the main psychological journals can’t be replicated to generate significance findings. This makes me dig a little further on how to conduct statistical tests. Let me show you my little experiments in `R` first. # remove(list=ls()) set.seed(19910715) n1 …
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Bayesian Network Augmented Naive-Bayes (BAN) is an improved version of Naive-Bayes, in which every attribute $latex X_i$ may have at most one other attribute as its parent other than the class variable $latex C$. For example (figure from [1]): Though BAN provides a more flexible structure compared to Naive Bayes, the structure (i.e., dependence/independence relationships …
It’s been half year since last time I studied LDA (Latent Dirichlet Allocation) model. I found learning something without writing them down can be frustrating when you start to review them after some while. Sometimes it is a bit embarrassing that you feel you didn’t learn that at all. Back to the topic, this post …
This post is a collection of hypothesis test methodologies. The full collection is listed here: http://www.biostathandbook.com/testchoice.html. My post just goes over several hypothesis tests that are relevant to my research. One-way ANOVA: http://www.biostathandbook.com/onewayanova.html If you have one measurement variable and one nominal variable, and the nominal variable separates subjects into multiple groups, you want to test …
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I’ve been scratching my head for a day (06/24/2015) but it ended up that I am still baffled by the concept of Factor Analysis. So first of all, let me list what I’ve learned so far today. PCA and Factor Analysis can be deemed similar from the perspective that they are both dimension reduction technologies. …
Long Short Term Memory is claimed to be capable of predicting time series when there are long time lags of unknown sizes between important events. However, as to 2015.6, not many clear tutorials have been found on the Internet. I am going to list a collection of materials I came across. Probably I will write …
Update 07/15/2015: First, we should know how to calculate covariance matrix and correlation matrix. According to the wikipedia page, we have the calculation procedure of covariance matrix as: And the calculation procedure of correlation matrix is: I am going to use an R example to illustrate the calculation procedures. Let’s say we have a …