Given a positive integer n. The problem is to check whether only the first and last bits are set in the binary representation of n.
Input : 9 Output : Yes (9)10 = (1001)2, only the first and last bits are set. Input : 15 Output : No (15)10 = (1111)2, except first and last there are other bits also which are set.
Approach: Following are the steps:
- If n == 1, return “Yes”.
- Else check whether n-1 is a power of 2. Refer this post.
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- Check if bits of a number has count of consecutive set bits in increasing order
- Check if all bits of a number are set
- Check whether the number has only first and last bits set | Set 2
- Check if a number has two adjacent set bits
- Check if a number has bits in alternate pattern | Set 1
- Check if a number has same number of set and unset bits
- Check if a number has bits in alternate pattern | Set-2 O(1) Approach
- Toggle bits of a number except first and last bits
- Check whether all the bits are set in the given range
- Check whether all the bits are unset in the given range or not
- Check whether all the bits are unset in the given range
- Check if bits in range L to R of two numbers are complement of each other or not
- Check whether bits are in alternate pattern in the given range
- Check whether bits are in alternate pattern in the given range | Set-2
- Maximize a given unsigned number number by swapping bits at it's extreme positions.
Improved By : Sach_Code