bitwise

bitwise

//is Unique: Implement an algorithm to determine if a //string has all unique characters. No additional 
//data tractures 

#include <iostream>
using namespace std;

//bruth force
bool isunique(string str){
	int checker=0;
	for(int i=0; i<str.size(); i++){
		int val=str[i]-'a';
		cout<<"Val = "<<val<<endl;
		cout<<"1<<val = "<<(1<<val)<<endl;
		if((checker&(1<<val))>0){ //shift 0 by 1, why is it one instead of 0?
			return false;
		}
		checker=checker|(1<<val); //shouldn't this and the "(1<<val)" above be same? it is not
		//also how a bool is assigned bigger number and what does that mean
		cout<<"checker = "<<checker; 
		cout<<endl<<endl;
	}
	return true;
}
int main(){
string str; 
str="abcde";

if(isunique(str))
	cout<<"yes";

return 0;
}