When a system administrator wants see when a user last changed a password or wants to force a user to change it, there is a really nice command to come to the rescue: chage. I created a user called aluno and I started to check for its information: $ sudo chage -l aluno Last password change : Sep 16, 2016 Password expires : never Password inactive : never Account expires : never Minimum number of days between password change : 0 Maximum number of days between password change : 99999 Number of days of warning before password expires : 7 As we see, the user password was last changed on Sep 16, 2016 and it never expires nor gets inactive....

The challenge for today is interesting, but I keep wondering if I could do it more efficiently. Let me know in the comments if you have any suggestion after reading my solution. The problem is counting the maximum number of consecutive binary ones in an integer. It is easier to understand with an example: Consider the number 25 represented in base 10 Its representation in binary is 11001 The max number of consecutive ones we can see is 2 What I did was shifting to the right and checking the least significant bit until every single bit of it was checked....

Hi there! Here I am coding again. For those of you readers who may not know what recursion is, I have a brief explanation: a function is called a recursive function when it calls itself. A very nice example is the factorial, which is also what I am going to code today. For the factorial of $N$, $f(N)$, we can state that $f(N) = N\times f(N-1)$. What we see is that the function is represented by itself, but with other argument and it can keep this going up to a certain point for which we know the answer like $f(1)=f(0)=1$....

Hi there! The task of today will be coding a phone book. The program reads an integer $N$ that represents the number of people in the phone book. After that, it reads the $N$ entries from standard output and generates the dictionary/map. For newbies: dictionaries are the same as maps. Java usually calls the structure with (key, value) pairs as a map, while Python calls it a dictionary. After having the phone book generated, the program will read an unknown number of names....

Hi there! A couple days ago I wrote a post about a simple array sum in Go and I said I didn’t need an array in memory to do the sum, but just an integer that would store the inputs the user gave the program. This time, I will really need an array. The goal is to read an array $A$ of $N$ elements and print $A$ elements in reverse order....

Some challenges require us to review basic concepts to make them work. This one is no different, but the main purpose of it is to be a review! The goal is to separate the characters of a string. The even-indexed characters will form a string and the odd-indexed characters will form another. These two strings must be printed to the screen with a space between them. Not hard, but an important review....

Hi there! Welcome to Day 5 of 30 days of code in Go! One interesting thing about loops in Go is that there is only one looping construct: for. This challenge will receive an integer input $N$ and it will print results of the form $N\times i = \mathrm{result}$, where $1 \le i \le 10$. By the way, there was a loop on the last day of code, but it was actually part of the given code....

Here I am again for the 30 Days of Code in Go. This is Saturday, but that doesn’t mean I will not code =). First of all, before starting to code I was thinking about the theme: classes. I was wondering if Go had support for it and I found some interesting material to read. First I read Why Go’s structs are superior to class-based inheritance and I found out the the inheritance model of Go is different from that of Java....

Hello again! I saw a problem in HackerRank to sum an array of elements. I have done this before in a couple of languages, but never in Go, so I was not sure exactly what to do. I coded the solution and it is: package main import "fmt" func main() { var n uint32 fmt.Scanf("%d\n", &n) sum := 0 current := 0 for n > 0 { fmt.Scanf("%d", ¤t) sum += current n-- } fmt....

The HackerRank challenge of today was a problem with conditionals. Given an integer $n$, the goal was to perform the following actions: If $n$ is odd, print Weird If $n$ is even and in the range $[2, 5]$, print Not Weird If $n$ is even and in the range $[6, 20]$, print Weird If $n$ is even and greater than $20$, print Weird The input to the program is simply the number $n$ and the result is a single line saying that the number is weird or not....