On Csharp - Covariance and Contravariance

Author: Son Nguyen Hoang

Word: 1645

Language: English

Created On: 12 Jun 2024

Useful concepts for generic interface, delegates and more!

Recently I decided to teach myself some C# knowledge that I found my self lacking, including but not limited to Task (Concurrency), delegates and some Design Patterns. While reading books, I encountered two concepts that sound pretty weird. They are Covariance and Contravariance. What are these? Problem I didn’t find any good translation to Vietnamese of these two concepts. The first result from Google indicates that Covariance is related to statistic? So, what are they? Definition Below here my own definition for some keywords: ...

Những Bóng Ảnh và Sao Mờ - Viết cho ông Phan

Author: Son Nguyen Hoang

Word: 3105

Language: Vietnamese

Created On: 20 Nov 2024

Chuyện thứ hai

Ông Phan mất rồi. Ông vừa qua đời hôm qua. Lúc ấy ở bên Đức có lẽ là năm giờ sáng. Mẹ tôi nhắn cho tôi từ chiều. Lúc ấy mẹ gửi đính kèm một tấm ảnh. Người trong ảnh ấy là một ông bác tóc bạc trạc tuổi ông ngoại tôi. Khuôn mặt người đó trong ảnh nở nụ cười lớn. Đôi lông mày cong cong, hệt như của ông ngoại. Vầng trán thì cao và rõ ràng, càng điểm xuyết cho cái nét hồng hào của người ấy. Nếu bác ấy mập lên nữa thì hẳn là giống với ông ngoại tôi lắm. Tôi thầm nghĩ hồi lâu rồi chợt nhận ra rằng hóa ra ngày ông Phan mất lại là ngày đầu tiên tôi nhìn mặt ông ấy. Thật trớ trêu làm sao. ...

Leetcode Fighter: Top K Frequent Elements

Author: Son Nguyen Hoang

Word: 1485

Language: English

Created On: 24 Dec 2024

Documents and study note for classic leetcode problem: Top K Frequent Elements

Top K Frequent Elements Problem Statement Given an integer array nums and an integer k, return the k most frequent elements within the array. The test cases are generated such that the answer is always unique. You may return the output in any order. Example 1: Input: nums = [1,2,2,3,3,3], k = 2 Output: [2,3] Example 2: Input: nums = [7,7], k = 1 Output: [7] Constraints: 1 <= nums.length <= 10^4. -1000 <= nums[i] <= 1000 1 <= k <= number of distinct elements in nums. A short analysis The problem super interesting. To be honest, I couldn’t figure out how to do until I read the second hint from Neetcode, that suggest grouping number based on their frequency ...

Tech Journal - VSCode, Extension, Debugging Error

Author: Son Nguyen Hoang

Word: 370

Language: English

Created On: 15 Nov 2024

A quick journey to fix a stupid, confusing bug

For the last few days I challenged myself to craft a small, lightweight extension on VScode. This is a tool I customized to ease some of the pain I had when working with Roblox. Getting used to VSCode Extension is fun - I have to admin. The API is clean and sharp, however, something had happened … Problem Some unwanted behavior occur I have to add code breakpoint to debug the extension but it not work. The breakpoint is unbound Printing on console is no work as well. However, the extension did running. Albeit, all the modifications I made seem to have no effect to fix the unwanted behavior What’s the heck is happening? ...


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