Codewars Exercises

Solutions to Problems Given on codewars.com

Exercise 1 (split_string.cpp)


Examples:

* 'abc' =>  ['ab', 'c_']
* 'abcdef' => ['ab', 'cd', 'ef']

Takes user input, enter a string, and it will split the string as required.

Exercise 2 (revwords.cpp)


Examples
"This is an example!" ==> "sihT si na !elpmaxe"
"double  spaces"      ==> "elbuod  secaps"

Takes user input, enter a string, and it will reverse each word while keeping it in the same index.

Reversing the entire string would have been trivial of course, even without 'reverse', but this is slightly more involved.

Exercise 3 (sumodd.cpp)


             1
          3     5
       7     9    11
   13    15    17    19
21    23    25    27    29
...
Calculate the sum of the numbers in the nth row of this triangle (starting at index 1) e.g.: (Input --> Output)

1 -->  1
2 --> 3 + 5 = 8

Simple cubed calculation.

Exercise 4 (esides.cpp)


For example:

Let's say you are given the array {1,2,3,4,3,2,1}:
Your function will return the index 3, because at the 3rd position of the array, the sum of left side of the index ({1,2,3}) and the sum of the right side of the index ({3,2,1}) both equal 6.

Let's look at another one.
You are given the array {1,100,50,-51,1,1}:
Your function will return the index 1, because at the 1st position of the array, the sum of left side of the index ({1}) and the sum of the right side of the index ({50,-51,1,1}) both equal 1.

Last one:
You are given the array {20,10,-80,10,10,15,35}
At index 0 the left side is {}
The right side is {10,-80,10,10,15,35}
They both are equal to 0 when added. (Empty arrays are equal to 0 in this problem)
Index 0 is the place where the left side and right side are equal.

Note: Please remember that in most programming/scripting languages the index of an array starts at 0.

Input:
An integer array of length 0 < arr < 1000. The numbers in the array can be any integer positive or negative.

Output:
The lowest index N where the side to the left of N is equal to the side to the right of N. If you do not find an index that fits these rules, then you will return -1.

Note:
If you are given an array with multiple answers, return the lowest correct index.

This was quite involved, due to the amount of rules given. As stated, give an array of various numbers, then add them up as required (increasing/decreasing indexes from right to left), store the sum in a container, compare the values, and return the index where the values match. If there are no matching values return -1.

All required tests pass, and it is valid, but something might be said about efficiency.

Exercise 5 (count.cpp)

DESCRIPTION:
The main idea is to count all the occurring characters in a string. If you have a string like aba, then the result should be {'a': 2, 'b': 1}.

What if the string is empty? Then the result should be empty object literal, {}.

As the description says, counts how many chars are present in a given string. It is way too long and a simpler solution is commented out.

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