Prove that in a bit string the string 01 occurs at most one
Prove that in a bit string, the string 01 occurs at most one more time than the string 10.
Solution
There can be two possible cases for the bit string
Case 1: String doesn\'t contain the bit pattern \"10\"
hence the string will be of the form
0*1* where * represents there will be continuous flow of 0\'s and continuous flow of 1\'s in the second *
Hence number of 01 pairs will be equal to 1
number of 0,1 pairs = 1 <= number of 1-0 pairs + 1
Hence the case 1 holds true
Case 2: String contains the patter 10
Method: Divide the string into two halves such that 1 is in the left substring and 0 is in the right substring
let s be the complete string and a,b be the sub-strings
then number of 0,1 pairs in a <= number of 1,0 pairs in a + 1
then number of 0,1 pairs in b <= number of 1,0 pairs in b + 1
adding both the equations we get
number of 0,1 pairs in s = number of 1,0 pairs in a + number of 1,0 pairs in b + 2 <= number of 1,0 pairs s + 1
Hence the given case also holds true
Therefore, we get that in a bit string, the string 01 occurs at most one more time than the string 10
