Kumite

Start a new Kumite

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.

Career Opportunities

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notradiochickenwax1

get height of binary tree

Given a binary tree defined as below, return the height of the tree.

class Node {
    constructor(val) {
        this.data = val;
        this.left = null;
        this.right = null;
    }
}```


Example:(TBD)

function treeHeight(node)
 {
     if (node == null)
         return 0;
     else
     {
         /* compute the height of each subtree */
         var lheight = treeHeight(node.left);
         var rheight = treeHeight(node.right);
 
         /* use the larger one */
         if (lheight > rheight)
         {
             return(lheight + 1);
         }
         else {
           return(rheight + 1);
         }
     }
 }

const chai = require("chai");
const assert = chai.assert
 a = new Node("A")
var b = new Node("B");
var c = new Node("C");
var d = new Node("D");
var e = new Node("E");
var f = new Node("F");
var g = new Node("G");

a.left = b;
a.right = c;
b.left = d;
b.right = e;
c.left = f;
c.right = g;

;
chai.config.truncateThreshold = 0;

describe("treeHeight", function() {
  it("given null", function() {
    assert.equal(treeHeight(null), 0);
  });  
  it("given a", function() {
    assert.equal(treeHeight(a), 3);
  });
  it("given b", function() {
    assert.equal(treeHeight(b), 2);
  });
  it("given c", function() {
    assert.equal(treeHeight(c), 2);
  });
  it("given d", function() {
    assert.equal(treeHeight(d), 1);
  });
  it("given e", function() {
    assert.equal(treeHeight(e), 1);
  });
  it("given f", function() {
    assert.equal(treeHeight(f), 1);
  });
  it("given g", function() {
    assert.equal(treeHeight(g), 1);
  });
  // TODO: non-existing value
});

Lukasz-Jasionowski

Is Greater Than?

Fundamentals

Numbers

Data Types

Logic

Write a method that returns a greater number.

Perfect task for begginers!
Welcome to CodeWars!

public class Math
{
  public int Max(int a, int b)
  {
    return (a > b) ? a : b;
  }
}

namespace Solution {
using NUnit.Framework;

  [TestFixture]
  public class SolutionTest
  {
     private Math math;

        [SetUp]
        public void SetUp()
        {
            math = new Math();
        }
        [Test]
        [TestCase(1,2,2)]
        [TestCase(2,1,2)]
        [TestCase(1,1,1)]
        public void Max_WhenCalled_ReturnTheGreaterArgument(int a, int b, int expectedResult)
        {
            var result = math.Max(a,b);

            Assert.That(result, Is.EqualTo(expectedResult));
        }
  }
}

wu850217

Failed Tests

wu850217's Kumite #2

# You can test with testthat (http://r-pkgs.had.co.nz/tests.html#test-structure)
# TODO: replace with your own tests (TDD), these are just here to demonstrate usage.

test_that("example", {
  expect_equal(actual, expected)
})
# You can test with testthat (http://r-pkgs.had.co.nz/tests.html#test-structure)
# TODO: replace with your own tests (TDD), these are just here to demonstrate usage.

test_that("example", {
  expect_equal(actual, expected)
})

MrSmiters

Once upon a time in the huge array

Write an implementation of a method:

@param a - array of numbers, array length can be greater than 10 million.
@return - array of numbers with no duplicates. The order of numbers in the original array must be preserved. The last element of the duplicates must be kept, e.g. for {2.0, 1.0, 4.0, 2.0, 3.0} the correct solution is {1.0, 4.0, 2.0, 3.0}, not {2.0, 1.0, 4.0, 3.0}!

In case there is an element less than 0.0 in the input array, output array{-1.0} should be given.
For example, for {2.0, 3.0, -1.0, 5.0} the processing should result {-1.0}.

Good luck...

import java.util.*;

class DeleteDuplicates {
  public static double[] delete(double[] a) { 
    
    for(int i = 0; i < a.length / 2; i++) {
      double temp = a[i];
      a[i] = a[a.length - i - 1];
      a[a.length - i - 1] = temp;
    }

    Set<Double> set = new LinkedHashSet<>();
    for (double v : a) {
      set.add(v);
      if(v < 0.0)
        return new double[]{-1.0};
    }

    List<Double> list = new ArrayList<>(set);
    Collections.reverse(list);

    double[] array_here = list.stream().mapToDouble(Double::doubleValue).toArray();
    
    //incorrect (too long and witout accuracy)
    
    return array_here;
  }
}

import java.util.*;
import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.assertEquals;

class SolutionTest {
  @Test
  void test1() {
    assertEquals(Arrays.toString(DeleteDuplicates.delete(new double[]{2.0, 1.0, 4.0, 2.0, 3.0})), 
                                                                      "[1.0, 4.0, 2.0, 3.0]");
  }
  
  @Test
  void test2() {
    assertEquals(Arrays.toString(DeleteDuplicates.delete(new double[]{2.0, 3.0, -1.0, 5.0})), 
                                                                      "[-1.0]");
  }
  
  @Test
  void test3() {
    assertEquals(Arrays.toString(DeleteDuplicates.delete(new double[]{2.2131141516, 1.234, 4.234, 
                                                                      2.2131, 3.0, 3.0, 
                                                                      12.321, 2.2131141516})), 
                                            "[1.234, 4.234, 2.2131, 3.0, 12.321, 2.2131141516]");
  }
}

Lukasz-Jasionowski

FizzBuzz

Fundamentals

Strings

Data Types

Logic

Write a function that returns string:

"Fizz" when the number is divisible by 3.
"Buzz" when the number is divisible by 5.
"FizzBuzz" when the number is divisible by 3 and 5.

public class FizzBuzz
 {
   public string GetOutput(int number)
   {
     if ((number % 3 == 0) && (number % 5 == 0))
       return "FizzBuzz";

     else if (number % 3 == 0)
       return "Fizz";

     else if (number % 5 == 0)
       return "Buzz";

    else return number.ToString(); 
   }
}

namespace Solution {
  using NUnit.Framework;
  [TestFixture]
  public class SolutionTest
  {
     [Test]
     public void GetOutput_InputIsDivisibleBy3_ReturnFizz()
     {
        var fizzbuzz = new FizzBuzz();
        var result = fizzbuzz.GetOutput(3);
        Assert.That(result, Is.EqualTo("Fizz"));
     }
     [Test]
     public void GetOutput_InputIsDivisibleBy5_ReturnBuzz()
     {
        var fizzbuzz = new FizzBuzz();
        var result = fizzbuzz.GetOutput(5);
        Assert.That(result, Is.EqualTo("Buzz"));
     }
     [Test]
     public void GetOutput_InputIsDivisibleBy5And3_ReturnFizzBuzz()
     {
        var fizzbuzz = new FizzBuzz();
        var result = fizzbuzz.GetOutput(15);
        Assert.That(result, Is.EqualTo("FizzBuzz"));
     }
  }
}

CarelGreylin

Chinese gift planner

Write the function optimal_gifts(gifts: int, recipients: int) -> int
You are given gifts number of gifts and recipients number of recipients.

Return the maximum number of recipients that can receive 8 gifts under the following conditions:

No recipient can recieve no gifts
No recipient can recieve 4 gifts
No recipient can receive more than 8 gifts
All gifts must be distibuted unless all recipients are already recveiving 8 gifts

Examples:

optimal_gifts(8, 2) returns 0
optimal_gifts(12, 2) returns 0
optimal_gifts(8, 1) returns 1
optimal_gifts(24, 2) returns 2
optimal_gifts(24, 3) returns 3
optimal_gifts(24, 4) returns 2

def optimal_gifts(gifts: int, recipients: int) -> int:
    kids = [1 for _ in range(gifts)]
    gifts -= recipients
    for i in range(recipients):
        while (gifts > 0 and kids[i] < 8):
            kids[i] += 1
            gifts -= 1

    eigths = sum([1 if kid == 8 else 0 for kid in kids])

    if 4 in kids:
        eigths -= 1
        
    return eigths

import codewars_test as test
# TODO Write tests
import solution # or from solution import example

# test.assert_equals(actual, expected, [optional] message)
@test.describe("Examples")
def test_group():
    @test.it("Example 1")
    def test_case1():
        test.assert_equals(optimal_gifts(8, 2), 0)
    @test.it("Example 2")
    def test_case1():
        test.assert_equals(optimal_gifts(12, 2), 0)
    @test.it("Example 3")
    def test_case1():
        test.assert_equals(optimal_gifts(8, 1), 1)
    @test.it("Example 4")
    def test_case1():
        test.assert_equals(optimal_gifts(24, 2), 2)
    @test.it("Example 5")
    def test_case1():
        test.assert_equals(optimal_gifts(24, 3), 3)
    @test.it("Example 6")
    def test_case1():
        test.assert_equals(optimal_gifts(24, 4), 2)

drednout

Do we have programmer's day today?

Always forget how to exact determine programmer's day. Some code may help do it exactly and without heavy calculations.

# How to check that target date is Programmer's day?

def is_programmers_day(date):
    return date.timetuple().tm_yday == 256

import codewars_test as test
from solution import is_programmers_day 
from datetime import datetime, date

@test.describe("Example")
def test_group():
    @test.it("test case")
    def test_case():
        test.assert_equals(is_programmers_day(datetime(2021, 9, 13)), True)
        test.assert_equals(is_programmers_day(datetime(2020, 9, 12)), True)
        test.assert_equals(is_programmers_day(date(2019, 9, 13)), True)
        test.assert_equals(is_programmers_day(date(2016, 9, 12)), True)
        test.assert_equals(is_programmers_day(date(2000, 9, 12)), True)

mimdl12

Failed Tests

Split Strings

package kata



func Solution(str string) []string {
  var res []string
  if len(str) % 2 != 0 {
    str += "_"
  }
  for i := 0; i < len(str); i+=2 {
    res = append(res, str[i:i+2])
  }
  return res
}
// TODO: replace with your own tests (TDD). An example to get you started is included below.
// Ginkgo BDD Testing Framework <http://onsi.github.io/ginkgo/>
// Gomega Matcher Library <http://onsi.github.io/gomega/>

package kata_test
import (
  . "github.com/onsi/ginkgo"
  . "github.com/onsi/gomega"
  . "codewarrior/kata"
)
var _ = Describe("Test Example", func() {
//   It("should test that the solution returns the correct value", func() {
//     Expect(Solution(1)).To(Equal(2))
//   })
})

VladyaRazumist

Approximate PI using random function

import random

def approximate_pi(n):
    # n - number of generated points, more points => more accuracy
    number_of_points_in_circle = 0
    total_number_of_points = 0

    for _ in range(n):
        x = random.uniform(0, 1)
        y = random.uniform(0, 1)

        # sqrt(x^2 + y^2) < 1 => (x,y) inside circle with r = 1; x^2 + y^2 < 1 => (x,y) inside circle
        if (x**2 + y**2 < 1):
            number_of_points_in_circle += 1

        total_number_of_points += 1

    # Pi * r^2 / (2r)^2 = number_of_points_in_circle / total_number_of_points (ratio of the area of a circle with radius r to the area of a square with side = 2r)
    # r=1 => Pi = number_of_points_in_circle * 4 / total_number_of_points
    return (number_of_points_in_circle * 4) / total_number_of_points
import codewars_test as test
# TODO Write tests
import solution # or from solution import example

# test.assert_equals(actual, expected, [optional] message)
@test.describe("Approximate Pi")
def test_group():
    @test.it("test case")
    def test_case():
        test.assert_equals(round(approximate_pi(1000000), 2), 3.14)

AlexFicachi

Testing

Simple test to see how creating Kumites work

This function should return the sum of a and b.

(1,2) => 3
(5,9) => 14
(-3,8) => 5

def add(a, b):
    return a + b

import codewars_test as test
# TODO Write tests
import solution # or from solution import example

# 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)
        test.assert_equals(solution.add(1,2),3)
        test.assert_equals(solution.add(5,9),14)
        test.assert_equals(solution.add(-3,8),5)

Freestyle Sparring

get height of binary tree

Is Greater Than?

Write a method that returns a greater number.

wu850217's Kumite #2

Once upon a time in the huge array

FizzBuzz

Write a function that returns string:

Chinese gift planner

Do we have programmer's day today?

Split Strings

Approximate PI using random function

Testing

You have not created any collections yet.

Freestyle Sparring

Write a method that returns a greater number.

Write a function that returns string:

Confirm

Collect: kata

You have not created any collections yet.