(product_id, start_date, end_date) is the primary key (combination of columns with unique values) for this table. Each row of this table indicates the price of the product_id in the period f...

You are given two strings `s` and `t`. String `t` is generated by random shuffling string `s` and then add one more letter at a random position. Return the letter that was added to `...

In MATLAB, there is a handy function called reshape which can reshape an m x n matrix into a new one with a different size r x c keeping its original data. You are given an m x n matrix m...

The “digital envelope routines::unsupported” error is a common issue that can occur in React.js projects when using outdated versions of Node.js or SSL packages. This error can be resolved by upd...

You are given an array coordinates, coordinates[i] = [x, y], where [x, y] represents the coordinate of a point. Check if these points make a straight line in the XY plane. Example 1: ...

This post includes the environment setup for Vue projects and creating Vue projects using Vue CLI. You can also find out how to store the preset of the Vue project settings and change the package m...

You are given a string s formed by digits and '#'. We want to map s to English lowercase characters as follows: - Characters ('a' to 'i') are represented by ('1' to '9') respectively. -...

Given a string `s`, return the string after replacing every uppercase letter with the same lowercase letter. Example 1:　 Input: s = "Hello", Output: "hello"　 Example 2:　 In...

You own a Goal Parser that can interpret a string command. The command consists of an alphabet of "G", "()" and/or "(al)" in some order. The Goal Parser will interpret "G" as the string "G", "...

You are given two strings `word1` and `word2`. Merge the strings by adding letters in alternating order, starting with `word1`. If a string is longer than the other, append the additional lett...