Test odd numbers — practice exercise

What you'll be asked to do

1. 1.Test odd numbersexercise · easy · 10 min

   Use a bitwise test to report whether seven is odd.

   Passes when: #out should show odd.

2. 2.Halve with a shiftexercise · easy · 10 min · practice plan

   Halve thirteen using a shift and show the result.

   Passes when: #out should show half 6.

3. 3.Count set bitsexercise · easy · 10 min · practice plan

   Count the one bits in thirteen.

   Passes when: #out should show bits 3.

4. 4.Find the lonely valueexercise · easy · 10 min · practice plan

   Every value appears twice except one — find it with XOR.

   Passes when: #out should show alone 4.

5. 5.Power of twoexercise · medium · 10 min · practice plan

   Report whether sixteen is a power of two.

   Passes when: #out should show power of two.

6. 6.Fix the odd test using modulo on a negativebug fix · easy · 8 min

   The remainder of a negative number is negative, so the equality fails.

   Passes when: #out should show odd.

7. 7.Fix the shift in the wrong directionbug fix · easy · 8 min · practice plan

   Shifting left doubles the value rather than halving it.

   Passes when: #out should show half 6.

8. 8.Fix the bit count clearing the wrong bitbug fix · medium · 8 min · practice plan

   Adding one instead of subtracting never clears a bit, so a guard stops it.

   Passes when: #out should show bits 3.

9. 9.Fix the lonely value found with additionbug fix · easy · 8 min · practice plan

   Summing does not cancel the pairs the way XOR does.

   Passes when: #out should show alone 4.

10. 10.Fix the 32-bit overflowbug fix · easy · 8 min · practice plan

    Bitwise operators truncate to 32 bits, so shifting by 32 wraps back to one.

    Passes when: #out should show exact.

Between them these tasks cover Masks, XOR and 32-bit limits.

Looking for a different chapter? See every practice set, or switch to the interview theory questions.