I got addicted to VS Code. I’ve fallen in love with this little bastard from Microhard. It’s convenient for Go, nothing to do with it… And for this very Go, you need to constantly loop with the console to run the project via go run . Doing it every time by hand is, of course, unkosher. So here’s what we do, Mikhalych:
Ctrl+Shift+pPreferences: Open keyboard shortcutsOpen keyboards shortcuts (JSON)1) Requires password all the time when starting pgAdmin 4 (which is irrelevant for localhost)
Solution:
go to C:\Program Files\PostgreSQL\15\pgAdmin 4\web\
make a copy of the file config.py
call it config_local.py
Change MASTER_PASSWORD_REQUIRED to False
2) By setting the bin folder to PATH, you can call from the terminal
psql
but get error: psql: error: connection to server at “localhost” (::1), port 5432 failed: FATAL: password authentication failed for user “vasya”
Solution:
run from regular user psql -U postgres
The problem is to find in an array of integers a sequence of consecutive numbers whose sum is equal to n.
Our program will read a list of integers (e.g., 5 2 3 4 6 1 4 10 1), followed by one integer n (e.g., 7). Example output:
5 2 3 4 6 1 4 10 1
7
5 + 2 = 7
3 + 4 = 7
6 + 1 = 7
Based on the list of dungeon raids, find the top player in the guild 🙂
Example of input:
Let’s look at some examples of slice programs in Go.
First one… The user enters two rows of numbers. Our task is to collect them in one slice, removing duplicates. As an exercise, we will not use cards, but ordinary slices.
Code:
Selection sort is a simple sorting algorithm that repeatedly selects the minimum item from the unsorted part of the list and swaps it with the first unsorted item.
Example code in Go:
О… how much is in this “Chink”-sound!.. We learned to sort by “bubble” back in school (hello, Mr.Obama!). Why not make a code for this sorting in Go? 😀 Even if it is seldom useful, it’s a good exercise for beginners.
Our program will take a string of integers separated by spaces, convert them to a slice of integers and sort the slice in ascending order… Code:
The user enters any number, letter, word, or whatever he wants, separated by a space. Let’s say he even enters card values (poker hand), such as A 3 J Q 10. Our job is to shuffle these cards.
To do this, it’s cool (and easy) to use the Fisher-Yates Algorithm. This algorithm works by iterating the array starting with the last element, and replacing the current element with a randomly chosen element. The process is repeated until the first element is reached. The result is a randomly shuffled array.
Here is my fiddly code for this “shuffle.”
Let’s write a simple console calculator that performs basic arithmetic operations. First, we give it the numbers with which we want to perform operations using the add <number> command (we can give several numbers). Then we can use the commands inc, acc, sub, mul, div, mod; to do calculations: we enter the index of the number to work with and then the operator arguments. Show can be used to display the numbers entered earlier; exit to exit the program.
Example output:
add 42 13
Operands: 42 13
inc 0 1
[43 13]
mod 1 3
[43 1]
exit
The most cumbersome for newcomers to golang are the interfaces. Here are some examples of code I took apart to “smoke” them, I hope they will help you too. The idea is to look at the code, then close it and from memory try to write from scratch according to this plan:
Example number one:
Assignment number 26 in the Go Tour.
Implement a Fibonacci function that returns a function (closure) that returns consecutive Fibonacci numbers (0, 1, 1, 1, 2, 3, 5, …).
Solution:
So, there we have exercise 23 from Go Tour.
Implement the WordCount function. It should return a map (data type map) of the counts of each “word” in the string s. The function wc.Test runs a set of tests against the provided function and outputs success or failure. It makes sense to use the strings.Fields function to perform the task.
Solution: Continue reading
From chapter 18 of Go tour.. In general, the tasks in this ‘tour’ are quite itchy B) So…
Implement the Pic function. It should return a fragment of length dy, each element of which is a fragment of dx 8-bit unsigned integers. When you run the program, it will display your picture by interpreting the integers as grayscale (or blue) values. It will draw something like the picture on the left..
Continue reading
The last example on Pythagoras’ theorem is quite simple. Let’s take a problem from the same topic, but more complicated. Suppose we have a circle in the center of x-axis and y-axis (i.e. center at coordinates 0,0). Let’s write a test for finding an arbitrary point inside the circle.
Here again Pythagoras will help us. In the general case, the formula is as follows:
Continue practicing Go and remembering the school curriculum “Pythagoras pants are equal on all sides!” Or to paraphrase in a more boring version: the square of the length of the hypotenuse of a right triangle is equal to the sum of the squares of the cathetuses: c^2 = a^2 + b^2
Our titanic task is this: find the third side of a right triangle. Here’s the code:
Let’s write a simple program in Go that will take a string, break it down into slice elements, and convert each element into a number.
First, all the code, and I will break it down in detail below: