human
Efficiently check if a string has all unique characters without using any additional data structure | Returns true if all characters of str are unique . Assumptions : ( 1 ) str contains only characters from ' a ' to ' z ' ( 2 ) integers are stored using 32 bits.
An integer to store presence / absence of 26 characters using its 32 bits.
If bit corresponding to current character is already set.
set bit in checker.
Driver code"
Solution in Python:
assistant
#Here is code to efficiently check if a string has all unique characters without using any additional data structure and the other steps required.
 def areCharactersUnique ( s ) :
	checker = 0
	for i in range ( len ( s ) ) :
		val = ord ( s [ i ] ) - ord ( ' a ' )
		if ( checker & ( 1 << val ) ) > 0 :
			return False
		checker |= ( 1 << val )
	return True
s = " aaabbccdaa "
if areCharactersUnique ( s ) :
	print ( " Yes " )
else :
	print ( " No " )