A light and fast code to count digit repetition in a number written in c.
0000 0000 0000 0000 0000 0000
6 5 4 3 2 1
- If we think an int 64bit as an array of bits you'll have something like this (if using 4bits in the BITS_LENGTH macro).
- Each 4bits can contains up to 1111 or 15 (decimal).
- We can consider each 4 bits block as a container which stores the repetion of the numbers.
for instance, if we have 2 occurance of 4 we'll have...
0000 0000 0010 0000 0000 0000
6 5 4 3 2 1
where 0010 in decimal is 2.