How do you convert 35 into 53 using bitwise operators?

Answer 1

22 XOR 35 = 53

Note that the value 22 is a magic number because it only works for the values 35 and 53. The value 22 was calculated as follows:

35 XOR 53 = 22

It can also be seen that:

22 XOR 53 = 35

It is assumed that you are actually looking for some bitwise operation that will reverse the digits in any number. You cannot do this because in order to determine the magic number for any given value, you first need to XOR the value with the reverse of the value, which means you must already know the reverse of the value.

To reverse any value that is not a multiple of 10, use the following function:

unsigned reverse (unsigned num) {

unsigned rev;

rev = 0;

while (num) {

rev *= 10;

rev += num % 10;

num /= 10;

}

return rev;

}

Note that reverse(10) is 1, not 01. If you want to convert trailing zeroes into leading zeroes, convert the number to a string and then reverse the string, returning the string rather than the numeric value.