11. toggle the ith bit

 

N = 15 , i=2

N = 1111 à 1011 (after reset the 2^nd bit)

 

i=1<<i;

 = 0100

N ^ i = 1111^0100

         = 1111

         = 0100

         = 1011 (2^nd bit from the right is toggled)

 

Code :

            

#include<bits/stdc++.h> using namespace std; int main() {     // if i-th bit = 0 make 1     // if i-th bit = 1 make 0     int t,n,i,f,ans;     cin>>t;     while (t--)     {         cin>>n;         f = 1<<i;         ans = n^f;         cout<<ans<<endl;     }   }