Link to my solution code :
https://ideone.com/rpi8V4
The basic idea , is that a self destructing string should have equal number of ones and zeroes , so check if the given input string has even length , if yes, then , find the number of zeroes that you need to convert to "1" (or vice-versa), to get a string which has 'x' zeroes and 'x' ones , where x = n/2(length of string :n) .
Hope it helps!