Given a number n, we need to count the total number of n digit numbers such that the sum of even digits is 1 more than the sum of odd digits. Here even and odd means positions of digits are like array indexes, for example, the leftmost (or leading) digit is considered as even digit, next to leftmost is considered as odd and so on.
Input: n = 2 Output: Required Count of 2 digit numbers is 9 Explanation : 10, 21, 32, 43, 54, 65, 76, 87, 98. Input: n = 3 Output: Required Count of 3 digit numbers is 54 Explanation: 100, 111, 122, ......, 980
We strongly recommend you to minimize your browser and try this yourself first.
This problem is mainly an extension of Count of n digit numbers whose sum of digits equals to given sum. Here the solution of subproblems depends on four variables: digits, esum (current even sum), osum (current odd sum), isEven(A flag to indicate whether the current digit is even or odd).
Below is Memoization based solution for the same.
Count of 3 digit numbers is 54
Thanks to Gaurav Ahirwar for providing above solution.
Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above
- Count numbers with difference between number and its digit sum greater than specific value
- Print all n-digit numbers with absolute difference between sum of even and odd digits is 1
- Count total number of digits from 1 to n
- Count numbers formed by given two digit with sum having given digits
- Count of n digit numbers whose sum of digits equals to given sum
- Count of N-digit numbers with all distinct digits
- Total number of non-decreasing numbers with n digits
- Count of Numbers in Range where first digit is equal to last digit of the number
- Count of numbers between range having only non-zero digits whose sum of digits is N and number is divisible by M
- Count Numbers in Range with difference between Sum of digits at even and odd positions as Prime
- Count n digit numbers divisible by given number
- Count Numbers with N digits which consists of odd number of 0's
- Count of Numbers in Range where the number does not contain more than K non zero digits
- Count Numbers with N digits which consists of even number of 0’s
- Count the number of digits of palindrome numbers in an array