Kumite (ko͞omiˌtā) is the practice of taking techniques learned from Kata and applying them through the act of freestyle sparring.
You can create a new kumite by providing some initial code and optionally some test cases. From there other warriors can spar with you, by enhancing, refactoring and translating your code. There is no limit to how many warriors you can spar with.
A great use for kumite is to begin an idea for a kata as one. You can collaborate with other code warriors until you have it right, then you can convert it to a kata.
use std::iter::Sum; fn sum<T: Copy + Sum>(arr: &[T]) -> T { arr.iter().copied().sum() }module Sum (Sum.sum) where- use std::iter::Sum;
import Prelude hiding (sum)sum :: [Word] -> Wordsum = foldr1 (+)- fn sum<T: Copy + Sum>(arr: &[T]) -> T {
- arr.iter().copied().sum()
- }
#[test] fn test() { assert_eq!(sum(&[1, 2, 3]), 6) }module SumSpec (spec) whereimport Prelude hiding (sum)import qualified Prelude as Pre (sum)import Sum (sum)import Test.Hspecspec :: Specspec = doit "tests" $ doSum.sum [1] `shouldBe` Pre.sum [1]- #[test]
- fn test() {
- assert_eq!(sum(&[1, 2, 3]), 6)
- }
fn fibonacci(n: usize) -> u128 { let (mut n1, mut n2) = (1, 1); for _ in 2..n { (n1, n2) = (n2, n1 + n2); } n2 }import java.util.HashMap;import java.util.Map;public class Fibonacci {private static Map<Integer, Long> memoizationMap = new HashMap<>();public static long calcFibo(int n) {if (n <= 1) {return n;}if (memoizationMap.containsKey(n)) {return memoizationMap.get(n);}long fiboValue = calcFibo(n - 1) + calcFibo(n - 2);memoizationMap.put(n, fiboValue);return fiboValue;}- fn fibonacci(n: usize) -> u128 {
- let (mut n1, mut n2) = (1, 1);
- for _ in 2..n {
- (n1, n2) = (n2, n1 + n2);
- }
- n2
- }
#[cfg(test)] mod tests { use super::*; use std::time::Instant; fn test_fibonacci(input: usize, expected: u128) { let start = Instant::now(); let output = fibonacci(input); let micros = start.elapsed().as_nanos() as f64 / 1_000.0; assert_eq!(output, expected); println!("Fibonacci({input}) = {output} and takes {micros:.3}µs"); } #[test] fn test() { test_fibonacci(1, 1); // <0.1µs test_fibonacci(2, 1); // <0.1µs test_fibonacci(4, 3); // <0.1µs test_fibonacci(8, 21); // <0.1µs test_fibonacci(16, 987); // <0.1µs test_fibonacci(32, 2178309); // ~0.1µs test_fibonacci(64, 10610209857723); // ~0.2µs test_fibonacci(128, 251728825683549488150424261); // ~0.3µs test_fibonacci(186, 332825110087067562321196029789634457848); // ~0.5µs } }import org.junit.jupiter.api.Test;import static org.junit.jupiter.api.Assertions.assertEquals;// TODO: Replace examples and use TDD by writing your own testsclass SolutionTest {@Testvoid testSomething() {int n = 6;long start = System.currentTimeMillis();Long fibo = Fibonacci.calcFibo(n);long end = System.currentTimeMillis();- #[cfg(test)]
- mod tests {
- use super::*;
- use std::time::Instant;
- fn test_fibonacci(input: usize, expected: u128) {
- let start = Instant::now();
- let output = fibonacci(input);
- let micros = start.elapsed().as_nanos() as f64 / 1_000.0;
- assert_eq!(output, expected);
- println!("Fibonacci({input}) = {output} and takes {micros:.3}µs");
- }
- #[test]
- fn test() {
- test_fibonacci(1, 1); // <0.1µs
- test_fibonacci(2, 1); // <0.1µs
- test_fibonacci(4, 3); // <0.1µs
- test_fibonacci(8, 21); // <0.1µs
- test_fibonacci(16, 987); // <0.1µs
- test_fibonacci(32, 2178309); // ~0.1µs
- test_fibonacci(64, 10610209857723); // ~0.2µs
- test_fibonacci(128, 251728825683549488150424261); // ~0.3µs
- test_fibonacci(186, 332825110087067562321196029789634457848); // ~0.5µs
System.out.println("Fibonacci(" + n + ") = "+ fibo + " and takes " +(end - start) + "ms");- }
- }
Fundamentals
Strings
from collections import deque def reverse_string(string): return string[::-1]- from collections import deque
- def reverse_string(string):
reversed_str = deque("")[reversed_str.appendleft(letter) for letter in string]return "".join(reversed_str)- return string[::-1]
import codewars_test as test from solution import reverse_string @test.describe("Solution") def a(): @test.it("should test for something") def a(): test.assert_equals(reverse_string('abc'), 'cba') test.assert_equals(reverse_string('123'), '321') test.assert_equals(reverse_string('a1b2c3'), '3c2b1a') test.assert_equals(reverse_string('Hello World!'), '!dlroW olleH') test.assert_equals(reverse_string('Capre diem'), 'meid erpaC') test.assert_equals(reverse_string('Lorem ipsum dolor sit amet!'), '!tema tis rolod muspi meroL') test.assert_equals(reverse_string('abcdefghijklmnopqrstuvwxyz'), 'zyxwvutsrqponmlkjihgfedcba')- import codewars_test as test
- from solution import reverse_string
- @test.describe("Solution")
- def a():
- @test.it("should test for something")
- def a():
- test.assert_equals(reverse_string('abc'), 'cba')
- test.assert_equals(reverse_string('123'), '321')
- test.assert_equals(reverse_string('a1b2c3'), '3c2b1a')
- test.assert_equals(reverse_string('Hello World!'), '!dlroW olleH')
- test.assert_equals(reverse_string('Capre diem'), 'meid erpaC')
test.assert_equals(reverse_string('Lorem ipsum dolor sit amet!'), '!tema tis rolod muspi meroL')- test.assert_equals(reverse_string('Lorem ipsum dolor sit amet!'), '!tema tis rolod muspi meroL')
- test.assert_equals(reverse_string('abcdefghijklmnopqrstuvwxyz'), 'zyxwvutsrqponmlkjihgfedcba')
fn add(a: i32, b: i32) -> i32 { a + b }namespace Solution{public class MyCalculator{public int Add(int a, int b){return a + b;}}- fn add(a: i32, b: i32) -> i32 {
- a + b
- }
#[test] fn test() { assert_eq!(add(1, 1), 2); }using NUnit.Framework;using Solution;namespace Tests{[TestFixture]public class MyCalculatorTests{[Test]public void Add_TwoNumbers_ReturnsSum(){// ArrangeMyCalculator calculator = new MyCalculator();int a = 5;int b = 7;int expectedResult = 12;// Actint actualResult = calculator.Add(a, b);// AssertAssert.AreEqual(expectedResult, actualResult);}}- #[test]
- fn test() {
- assert_eq!(add(1, 1), 2);
- }
A function that returns the multiplication of the input arguments. Any number of input arguments can be used.
function multiply(...nums){ return nums.reduce((acc, num) => acc * num, 1) }# def multiply (a,b):# return a * bmultiply = lambda a, b: a * b- function multiply(...nums){
- return nums.reduce((acc, num) => acc * num, 1)
- }
const chai = require("chai"); const assert = chai.assert; describe("Multiply", function() { it(`input: 1`, function() { assert.strictEqual(multiply(1), 1); }); it(`input: 1, 2`, function() { assert.strictEqual(multiply(1, 2), 2); }); it(`input: 1, 2, 3`, function() { assert.strictEqual(multiply(1, 2, 3), 6); }); it(`input: 2, 2, 2, 2`, function() { assert.strictEqual(multiply(2, 2, 2, 2), 16); }); });import codewars_test as test# TODO Write testsimport solution # or from solution import example- const chai = require("chai");
- const assert = chai.assert;
# test.assert_equals(actual, expected, [optional] message)@test.describe("Example")def test_group():@test.it("test case")def test_case():test.assert_equals(1 + 1, 2)- describe("Multiply", function() {
- it(`input: 1`, function() {
- assert.strictEqual(multiply(1), 1);
- });
- it(`input: 1, 2`, function() {
- assert.strictEqual(multiply(1, 2), 2);
- });
- it(`input: 1, 2, 3`, function() {
- assert.strictEqual(multiply(1, 2, 3), 6);
- });
- it(`input: 2, 2, 2, 2`, function() {
- assert.strictEqual(multiply(2, 2, 2, 2), 16);
- });
- });
fn greeting(name: &str, formal_rank: Option<&str>) -> String { if let Some(title) = formal_rank { format!("Hello, {title} {name}.") } else { format!("Hey {name}!") } }class greeting:def __init__(self, name: str, formal: bool = False):self.name = nameself.formal = formaldef __call__(self) -> str:if self.formal: return f'Hello, Sir {self.name}.'else: return f'Hello, {self.name}!'g1 = greeting('John')g2 = greeting('Churchill', True)print(g1()) # 'Hello, John!'print(g2()) # 'Hello, Sir Churchill.'- fn greeting(name: &str, formal_rank: Option<&str>) -> String {
- if let Some(title) = formal_rank {
- format!("Hello, {title} {name}.")
- } else {
- format!("Hey {name}!")
- }
- }
#[cfg(test)] mod tests { use super::*; #[test] fn test_formal() { assert_eq!(greeting("Alice", Some("Professor")), "Hello, Professor Alice."); assert_eq!(greeting("Alex", Some("Viceroy")), "Hello, Viceroy Alex."); assert_eq!(greeting("Perry", Some("Agent")), "Hello, Agent Perry."); } #[test] fn test_informal() { assert_eq!(greeting("Jane", None), "Hey Jane!"); assert_eq!(greeting("Bob", None), "Hey Bob!"); assert_eq!(greeting("Mori", None), "Hey Mori!"); } }import codewars_test as test# TODO Write testsimport solution # or from solution import example- #[cfg(test)]
- mod tests {
- use super::*;
- #[test]
- fn test_formal() {
- assert_eq!(greeting("Alice", Some("Professor")), "Hello, Professor Alice.");
- assert_eq!(greeting("Alex", Some("Viceroy")), "Hello, Viceroy Alex.");
- assert_eq!(greeting("Perry", Some("Agent")), "Hello, Agent Perry.");
- }
- #[test]
- fn test_informal() {
- assert_eq!(greeting("Jane", None), "Hey Jane!");
- assert_eq!(greeting("Bob", None), "Hey Bob!");
- assert_eq!(greeting("Mori", None), "Hey Mori!");
- }
- }
# test.assert_equals(actual, expected, [optional] message)@test.describe("Example")def test_group():@test.it("test case")def test_case():test.assert_equals(greeting('John')(), 'Hello, John!')test.assert_equals(greeting('Churchill', True)(), 'Hello, Sir Churchill.')