Snippets

Here we archive snippets for input/output handling on different languages.

Contributing

The official repository is https://github.com/coding-gym/snippets

Anyone is encouraged to contribute, adding new languages or typical input/output cases.

Reading an array of N elements

The first line contains N, the number of elements.

The next line contains N space-separated integers.

Premise To be more exact, we should include all the needed headers first. For example: 1 2 3 4 #include <iostream> // for I/O #include <iterator> // for istream_iterator #include <vector> // for vector #include <string> // for string Actually, since we are usually hosted on machines with GCC, we can include only: 1 #include <bits/stdc++.h> Which makes everything from the STL available. Remember this header is not standard. Reading an array of N elements The first line contains N, the number of elements. [Read More]

The interact function The interact function takes a function of type String -> String as its argument. The entire input from the standard input device is passed to this function as its argument, and the resulting string is output on the standard output device. Predicate on strings Example: Balanced Brackets Input: 1 2 3 4 3 {[()]} {[(])} {{[[(())]]}} Output: 1 2 3 YES NO YES The first line contains a single integer n, the number of strings. [Read More]

Premise The needed imports should be already provided, in any case be sure to include: 1 2 import java.io.*; // for BufferedWriter import java.util.*; // for Scanner Reading values For reading we can use the java.util.Scanner class. We can create it in the main method. Remember to close it at the end. 1 2 3 4 5 public static void main(String[] args){ Scanner scanner = new Scanner(System.in); //data reading code scanner. [Read More]

Reading strings We can read a single line string using the built-in functions process.stdin: To fetch data from a stdin you can use process.stdin and send fetching result to a custom parsing function (parsingFunction) Following examples assume you are implementing parsingFunction content 1 2 3 4 5 6 7 8 9 10 11 process.stdin.resume(); process.stdin.setEncoding("ascii"); let fetchedInput = ""; process.stdin.on("data", function (input) { fetchedInput += input; }); process.stdin.on("end", function () { // call here your parsing function console. [Read More]

Reading strings We can read a single line string using the built-in functions fscanf() where %s operator casts input stream as a string: 1 2 $s = ''; fscanf(STDIN, "%s\n", $s); or fgets() 1 $s = trim(fgets(STDIN)); Reading an array of integers When you need to read an array of integers, you have to read the entire string line and then convert it in array using explode() built-in function. For instance, if your input line is 2 10 24 3 5 25, here is the snippet you’ll need: [Read More]

Reading strings We can read a single line string using the built-in functions input(): 1 a_line_read = input() Reading an array of integers When you need to read an array of integers, you have to read the entire line, split it and the convert each element to an int: 1 a_list_of_nums = map(int, input().split()) Reading n rows made up of a single integer 1 2 for n in range(10): single_int = map(int, input()) Writing on STDOUT When you need to write on stdout use: [Read More]

Premise At to date, HackerRank does not give you anything more than a Write you code here. If you take into account that the version of the compiler is a bit old, it is a bit slow to compile, no completion or rustfmt… It is not exactly a pleasure to code in Rust on HackerRank. So… let’s open your favorite IDE/Editor on steroids and copy-paste your solution to HR! You can also try The Rust Playground! [Read More]

Reading line We can read a single line string using the built-in method readLine from scala.io.StdIn: 1 2 3 import scala.io.StdIn._ val input: String = readLine Reading a list of integers When you need to read a list of integers, you have to read the entire line, split it and the convert each element to an int: 1 2 3 import scala.io.StdIn._ val listOfNumbers: List[Int] = readLine.split(" ").map(_.toInt) Reading first line with n, where n is number of rows made up of a single integer 1 2 3 import scala. [Read More]