Hello,

The Google Code Jam 2022 qualification round has started and it's a good opportunity to practice programming language skills. I wonder if there will be many nice and clean solutions submitted in D language? We can discuss them after the contest.

https://codingcompetitions.withgoogle.com/codejam/schedule

A plot twist. I actually used Golang for submitting all my solutions in the qualification round:
https://codingcompetitions.withgoogle.com/codejam/submissions/0000000000876ff1/000000000048a518

The reason is that right now I'm switching to Golang at work. And Code Jam tasks are a good practice to become more comfortable with new programming languages, considering that the qualification round had no strict time limit. It's also a good chance to compare Golang vs. Dlang for this kind of activity.

Below are a few solutions for the second task of the qualification round "3D Printing": https://codingcompetitions.withgoogle.com/codejam/round/0000000000876ff1/0000000000a4672b

Golang:

package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

var reader *bufio.Reader = bufio.NewReader(os.Stdin)
var writer *bufio.Writer = bufio.NewWriter(os.Stdout)

func printf(f string, a ...interface{}) { fmt.Fprintf(writer, f, a...) }
func scanf(f string, a ...interface{})  { fmt.Fscanf(reader, f, a...) }

// From https://stackoverflow.com/questions/27516387/what-is-the-correct-way-to-find-the-min-between-two-integers-in-go
func MinOf(vars ...int) int {
	min := vars[0]
	for _, i := range vars {
		if min > i {
			min = i
		}
	}
	return min
}

// From https://stackoverflow.com/questions/37532255/one-liner-to-transform-int-into-string
func SplitToString(a []int, sep string) string {
	if len(a) == 0 {
		return ""
	}
	b := make([]string, len(a))
	for i, v := range a {
		b[i] = strconv.Itoa(v)
	}
	return strings.Join(b, sep)
}

func main() {
	defer writer.Flush()
	var t int
	scanf("%d\n", &t)
	for casenum := 1; casenum <= t; casenum++ {
		var p1 = make([]int, 4)
		var p2 = make([]int, 4)
		var p3 = make([]int, 4)
		var ans = make([]int, 4)
		scanf("%d %d %d %d\n", &p1[0], &p1[1], &p1[2], &p1[3])
		scanf("%d %d %d %d\n", &p2[0], &p2[1], &p2[2], &p2[3])
		scanf("%d %d %d %d\n", &p3[0], &p3[1], &p3[2], &p3[3])
		todo := 1000000
		for i := 0; i < 4; i++ {
			ans[i] = MinOf(p1[i], p2[i], p3[i], todo)
			todo -= ans[i]
		}
		if todo > 0 {
			printf("Case #%d: IMPOSSIBLE\n", casenum)
		} else {
			printf("Case #%d: %s\n", casenum, SplitToString(ans, " "))
		}
	}
}

Ruby or Crystal:

1.upto(gets.to_s.to_i) do |casenum|
  todo = 1000000
  a = 3.times.map { gets.to_s.split.map {|x| x.to_i } }.to_a.transpose.map do |x|
    todo -= (result = [todo, x.min].min)
    result
  end
  printf("Case #%d: %s\n", casenum, todo > 0 ? "IMPOSSIBLE" : a.join(" "))
end

Dlang:

import std.algorithm, std.stdio, std.string, std.conv, std.range;

void main()
{
  foreach (casenum ; 1 .. readln.strip.to!int + 1) {
    auto todo = 1000000;
    auto a = zip(readln.splitter.map!(to!int),
                 readln.splitter.map!(to!int),
                 readln.splitter.map!(to!int)).map!"a[].min".array;
    foreach (ref x ; a)
      todo -= (x = min(todo, x));

    if (todo > 0)
      writefln("Case #%d: IMPOSSIBLE", casenum);
    else
      writefln("Case #%d: %(%s %)", casenum, a);
  }
}

Now which of these solutions is better? Getting a solution ready as fast as possible is usually very important in programming competitions, so expressive programming languages and smaller source code size is a clear advantage. That's why normally my primary choice would be Dlang (because Crystal is not supported by Code Jam, Codeforces and Codechef platforms at the moment).

But Golang is a simple language with no advanced features and syntax sugar, so it's easier for beginners to read and understand the code. From the practical point of view this is also useful and may be sometimes preferable in real projects. Python is easier than Ruby and is more popular. Golang is easier than Dlang and is more popular too.

I'm going to switch back to Dlang in the upcoming Round 1.

Now all three parts of the round 1 are over and finalized. There's a third-party website, which provides some stats: https://cpjsmith.uk/gcj/year?year=2022

It's interesting that D is one of the least popular programing languages with only a single digit number of users. It never managed to gain traction for some reason even in this niche. Yes, I know that there's a big discussion in another forum thread about why D is unpopular in general: https://forum.dlang.org/post/axslxubumvtrudpjfpng@forum.dlang.org

In programming competitions the experimental nature of the programming language and never ending compatibility breakages are a non-issue, because there's no need to maintain the written code over the span of many years. So it may seem that D should be a very good choice for programming competitions, but there's still no success. And it's not just the usual domination of C++ and Python languages. Rust is happily eating D's lunch.

On Friday, 6 May 2022 at 04:26:13 UTC, Siarhei Siamashka wrote:

Yes, Rust has intercepted d's most users.
However, a good meal is not afraid of late . Make up the language and compete with them.

On Friday, 6 May 2022 at 06:57:40 UTC, zjh wrote:

C++, Rust and python all have the biggest feature, that is, they pay attention not only to the language, but also to the library!
D language should be the same!
For example, I think d can also make use of 'winrt', which is very important for GUI programming . D officials should pay attention to it.

I have downloaded dwinrt and has many compilation errors!

D should lead the development of important libraries in d . and give a link to excellent libraries on the home page!

On Friday, 6 May 2022 at 06:57:40 UTC, zjh wrote:

We should even track the main libraries of major languages and have professionals write their ports to D.

There should also be news about major language/major libraries's major news or actions.Instead of just focusing on our own language.

On Friday, 6 May 2022 at 07:13:06 UTC, zjh wrote:

In addition, D should not be positioned as one's second language, but as first language.
We should position ourselves in comfort and make programmers feel good.

Only when the "programmers" are comfortable, naturally, they will come.
let D == a language that makes you comfortable.

On Friday, 6 May 2022 at 07:05:35 UTC, zjh wrote:

Regularly introducing compatibility breaking changes in the language and effectively pulling the rug from under the developer's feet can make maintaining a medium or large project rather expensive. And I guess, a lot of people hesitate to use D language in production because of this reason. The old code bitrots and stops compiling. Not everyone is ready to pay this tax. Long term maintenance is just much cheaper when using the other programming languages.

But again, programming competitions are all about just writing quick and dirty disposable code. If my solution submitted in a programming contest is going to stop compiling by a future version of the compiler, then I couldn't care less. So one of the major D language disadvantages has no real impact on its suitability for programming competitions. At least in theory. But maybe I'm missing something?

On Friday, 6 May 2022 at 08:25:34 UTC, Siarhei Siamashka wrote:

I remember someone proposed to build a software to automatically patch the code.