Code with undefined behavior

(*values)*(*values++)

Order of evaluation of the operands of any C operator, including the order of evaluation of function arguments in a function-call expression, and the order of evaluation of the subexpressions within any expression is unspecified (except where noted below). The compiler will evaluate them in any order, and may choose another order when the same expression is evaluated again."
https://en.cppreference.com/w/c/language/eval_order

This code can take \*values from right part, increment, and take next element of array for multiplication.

• count-- evaluates count and then decrements it. In C 0 has a false boolean value, so the loop will stop when count is 0
• incrementing/decrementing a pointer to type T will add/subtract sizeof T to the pointer address, so values++ will jump to the next element of values
• *values++ will first evaluate *values and then increment values. This is being overly clever with operator priority. *(values++) would have been clearer
• last but not least: this code is wrong. It contains undefined behavior because the C specification does not guarantee the order of operations in (*values) * (*(values++)). Just because it is written left-to-right does not mean it will be evaluated left-to-right. This code just happens to work.

Be careful with top voted solutions on Codewars, they are usually garbage

I have no idea how this code works, can someone expalin this to my dumb self...

LOL, seems not quite in the spirit of the kata, but yes this works!

why is this so upvoted?

Adds one space character after the element unless its the last element. But this solution is invalid anyway. It doesn't return pairs but single Strings instead with the comma at the right place so it passes the tests which unfortunately make use of Arrays.deepToString instead of comparing the array contents directly.

Hi, I undstand everyline but these
if(j != arr.length - 1)
a[i][0] += " ";

can anyone explain it ?

Thanks. The bitwise operator is hard to understand tho.

clever.

this is new to me. I am beginner. can anyone explain this?

this is the only solution that makes sense to me. hahah