How to find the largest number with given digit sum s and number of digits d?
Input : s = 9, d = 2 Output : 90 Input : s = 20, d = 3 Output : 992
A Simple Solution is to consider all m digit numbers and keep track of maximum number with digit sum as s. A close upper bound on time complexity of this solution is O(10m).
There is a Greedy approach to solve the problem. The idea is to one by one fill all digits from leftmost to rightmost (or from most significant digit to least significant).
We compare the remaining sum with 9 if the remaining sum is more than 9, we put 9 at the current position, else we put the remaining sum. Since we fill digits from left to right, we put the highest digits on the left side, hence get the largest number.
Below image is an illustration of the above approach:
Below is the implementation of the above approach:
Largest number is 90
Time Complexity of this solution is O(m).
This article is contributed by Vaibhav Agarwal. If you like GeeksforGeeks and would like to contribute, you can also write an article and mail your article to firstname.lastname@example.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.
Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above
- Find largest number smaller than N with same set of digits
- Find the largest number that can be formed by changing at most K digits
- Find the Largest Cube formed by Deleting minimum Digits from a number
- Find the average of k digits from the beginning and l digits from the end of the given number
- Find smallest number with given number of digits and sum of digits
- Largest number with the given set of N digits that is divisible by 2, 3 and 5
- Largest number with prime digits
- Largest number not greater than N all the digits of which are odd
- Largest palindromic number by permuting digits
- Count of integers in a range which have even number of odd digits and odd number of even digits
- Largest number not greater than N which can become prime after rearranging its digits
- Largest number smaller than or equal to n and digits in non-decreasing order
- Check whether product of digits at even places is divisible by sum of digits at odd place of a number
- Count of numbers between range having only non-zero digits whose sum of digits is N and number is divisible by M
- Maximize the given number by replacing a segment of digits with the alternate digits given
Improved By : jit_t