Given an integer n, the task is to count the total lucky numbers smaller than or equal to n. A number is said to be lucky if it has all contagious number of 1’s in binary representation from the beginning. For example 1, 3, 7, 15 are lucky numbers, and 2, 5 and 9 are not lucky numbers.
Input :n = 7 Output :3 1, 3 and 7 are lucky numbers Input :n = 17 Output :4
Approach:one approach is that first we find out the binary representation of each number and than check for contagious number of 1’s for each number, but this approach is time consuming and can give tle if the constraints are two large, Efficient approach can be find out by observing the numbers, we can say that every ith lucky number can be found by the formula 2i-1, and by iterating a loop upto number less than equal to n we can find out the total lucky numbers.
Below is the implementation of above approach
- 1 to n bit numbers with no consecutive 1s in binary representation.
- Longest common substring in binary representation of two numbers
- Count number of trailing zeros in Binary representation of a number using Bitset
- Count of Binary Digit numbers smaller than N
- Maximum 0's between two immediate 1's in binary representation
- Binary representation of next number
- Largest number with binary representation is m 1's and m-1 0's
- Binary representation of previous number
- Next greater number than N with exactly one bit different in binary representation of N
- Decimal representation of given binary string is divisible by 10 or not
- Decimal representation of given binary string is divisible by 5 or not
- Prime Number of Set Bits in Binary Representation | Set 2
- Length of the Longest Consecutive 1s in Binary Representation
- Check if binary representation of a number is palindrome
- Prime Number of Set Bits in Binary Representation | Set 1
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