All Questions
Tagged with programming-challengecombinatorics
70 questions
1vote
1answer
106views
Finding the number of distinct decompositions a number has using only repdigits
This is a problem from a previous semester that I am trying to upsolve. I am trying to solve a problem involving the total number of ways of decomposing a number using only repdigits. A repdigit is a ...
7votes
2answers
1kviews
Find all combinations of length 3 whose sum is divisible by a given number
I came up with a suitable solution to a HackerRank problem that failed because the execution took longer than 10 seconds on lists that were of very large size. The problem: Given a list ...
2votes
2answers
800views
Subarrays with length
You are given an array A of length N (where N is as large as 2×105). All elements of the array are positive integers less than or equal to N. Determine the count of subarrays (contiguous subsequences) ...
1vote
2answers
363views
Next different permutation in C
This is a program which you can get the next "different", i.e. elements in A[] can be identical, permutation at each call. I've written a C++ program for ...
- 541
8votes
3answers
294views
Refactor the code which performs "cross-product", "reduce", "product of list" and "sum of list"
I have come up with a sequence of steps to find the maximum product of y positive numbers which add up to x. But the program is ...
- 227
7votes
2answers
1kviews
Letter Combinations of a phone number using a Dictionary
Problem statement (online source) Given a digit string, return all possible letter combinations that the number could represent. A mapping of digit to letters (just like on the telephone ...
- 103
10votes
1answer
2kviews
Earliest time frog can jump to the other side of a river in C#
I'm new to C#, I programmed a little in Java in the past. I had the two previous exercises reviewed here (permCheck, cyclicRotation, with a 100% score, just like this one), and I'm applying what the ...
- 879
6votes
2answers
2kviews
Codility's Permutation Check in C#
I've made a few things in Java, and now I'm learning C#. The code passes the tests with 100% final score. I want to know what things can be improved in my code. Task description A non-empty array ...
- 879
2votes
2answers
561views
Counting block combinations I: Project Euler 114
Problem statement (For more detailed description (including pictures), please, visit the link): A row measuring seven units in length has red blocks with a minimum length of three units placed on ...
4votes
1answer
648views
Counting Bouncy Numbers: Project Euler #113
Problem statement: Working from left-to-right if no digit is exceeded by the digit to its left it is called an increasing number; for example, 134468. Similarly if no digit is exceeded by the ...
2votes
3answers
3kviews
Counting numbers that are divisible by 3 and can be produced from the digits of a given number
I'm trying to solve this problem from codewars. Problem Given a certain number, how many multiples of three could you obtain with its digits? Suppose that you have the number ...
11votes
3answers
978views
Print sums of all subsets
Print sums of all subsets of a given set Problem summary : Print all subset sums of a given set of integers My approach is to store previous results and use them to calculate new (similar idea as DP). ...
- 213
3votes
2answers
354views
Challenge: phone keypad to letters - return all possible strings
The challenge: Given a mapping of digits to letters (as in a phone number), and a digit string, return all possible letters the number could represent. You can assume each valid number in the ...
- 855
2votes
2answers
982views
Project Euler # 24 Lexicographic permutations in Python
A permutation is an ordered arrangement of objects. For example, 3124 is one possible permutation of the digits 1, 2, 3 and 4. If all of the permutations are listed numerically or alphabetically, we ...
user203258
4votes
2answers
765views
Letter case permutation
The question can be found here https://leetcode.com/problems/letter-case-permutation Given a string S, we can transform every letter individually to be lowercase or uppercase to create another ...
user172231
