What's wrong??

Question

https://code.sololearn.com/cTMfdEUc22YH/?ref=app

Answer 1

Swap function does not effect on original values, Since you are doing it by call by value, not by reference.
Swap values in loop itself...
Edit: alternatively use @zemiak suggestion.

Answer 2

You can do directly by print string backwards.
-----------------------------------------------------
-----------------------------------------------------
for(int i = s.length()-1; i>=0; i--){
System.out.print(s.charAt(i));
}
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Answer 3

use
swap(c, i, j);
...
public static void swap(char[] arr, int a, int b){

Answer 4

https://code.sololearn.com/c5N0egsInLgp/?ref=app

Answer 5

Thank guys