In real time production code is this recommneded ? since it's not a part of C standard.

Hmm, arr is a pointer to a const integer, good use of arr here.

It's crazy how people are good in using bitwise operators.

should have given you a warning for not including math.h library file.
plus stdio.h file is not required here as you are not performing any IO.

Amazing Kata !

True, excellent Kata, your hint should be included in the description.

Thanks

Read the How it worked part of the kata's description, you can't change horses or hand over the mail bag in the middle of nowhere, only at stations.

Distance          Rider number
19 + 67 = 86      1
34 + 20 + 41 = 95 2
85                3
47                4
65 + 28 = 93      5
54                6
69                7
56 + 6            8
71                9
60                10
88                11
15 + 24           12
77                13
64                14
94                15
98                16
65 + 1            17
42 + 28 + 23 = 93 18
81                19
67                20
35 + 16 = 51      21
85 + 2 = 87       22
50 + 4 + 43 = 97  23

And that's how each rider doesn't ride more than 100 miles each in that case.

Clever use of do while in this Kata !

consider the below array (one of the random test)

{19, 67, 34, 20, 41, 85, 47, 65, 28, 54, 69, 56, 6, 71, 60, 88, 15, 24, 77, 64, 94, 98, 65, 1, 
42, 28, 23, 81, 67, 35, 16, 85, 2, 50, 4, 43}

The total sum is 1724 of the entire array
each rider is capable to travel till 100 km
based on that info:
17 * 100 = 1700 (17 riders)
24 = 1 rider
total 18 riders can cover the distance mentioned in array.

But the test says it requries 23 riders, how is it calculated ?
can someone help me ? I'm not sure where I'm getting it wrong.

Very good kata !, should be 7 Kyu.

you need to add one more example, it's unclear what's the expecation here.

In music theory, this is called an inverse interval.

is this some mathematical formula ? what's it called ?

I want to know what made all you guys use a bitwise operator to get the answer ?
is it through expirience ? how one decides all this ?