Python program to count total set bits in all number from 1 to n.

Given a positive integer n, then we change to its binary representation and count the total number of set bits.

Example

Input : n=3
Output : 4

Algorithm

Step 1: Input a positive integer data.
Step 2: then convert it to binary form.
Step 3: initialize the variable s = 0.
Step 4: traverse every element and add.
Step 5: display sum.

Example Code

# Python program to count set bits
# in all numbers from 1 to n.
def countbits(n):
   # initialize the counter
   c = 0
   for i in range(1, n + 1):
   c += bitsetcount(i)
   return c
   def bitsetcount(x):
      if (x <= 0):
      return 0
      return (0 if int(x % 2) == 0 else 1) + bitsetcount(int(x / 2))
      # Driver program
      n = int(input("Enter the value of n"))
print("Total set bit count is", countbits(n))

Output

Enter the value of n10
Total set bit count is 17