Tagged Questions
17
votes
5answers
852 views
Count distinct primes, discarding palindromes, in under 2 seconds
Problem Statement
Generate as many distinct primes P such that reverse (P) is also prime
and is not equal to P.
Output:
Print per line one integer( ≤ 1015 ). Don't print more than
...
11
votes
3answers
858 views
The Love-Letter Mystery
Problem Statement
James got hold of a love letter that his friend Harry has written for
his girlfriend. Being the prankster that James is, he decides to
meddle with it. He changes all the ...
7
votes
2answers
136 views
Lychrel calculator (Project Euler 55)
If we take 47, reverse and add, 47 + 74 = 121, which is palindromic.
Not all numbers produce palindromes so quickly. For example,
...
6
votes
3answers
904 views
Project Euler #4 - Largest Palindrome Product
Problem Statement:
A palindromic number reads the same both ways. The largest palindrome
made from the product of two 2-digit numbers is 9009 = 91 × 99.
Find the largest palindrome made ...
6
votes
1answer
257 views
Finding the largest mirror image of a subset/set of integers present in an array of integers
The problem I am talking about is this.
Problem statment:
We'll say that a "mirror" section in an array is a group of contiguous
elements such that somewhere in the array, the same group ...
4
votes
6answers
1k views
Determining numeric palindromes
I am working on bettering my C# skills, and recently wrote this program to solve a projecteuler.net problem:
A palindromic number reads the same both ways. The largest palindrome
made from the ...
3
votes
1answer
110 views
Minimum number of letters removed, to make a string Peragram
Here is the link to the problem Peragrams.
Peragrams: If a word is an anagram of at least one palindrome, we call it a Peragram.
Problem: Given a string, find the minimum number of letters ...
2
votes
2answers
357 views
Project Euler, #4: Incorrect Results on 7-digit numbers
I've got my answer working (up until a 7-digit answer is requested, anyway), and would like some help
returning the correct answer
speeding up the results
I was thinking of storing the values of ...
1
vote
3answers
81 views
Optimizing Project Euler 36 - double-base palindromes
This one was quick and simple. Any optimizations?
...
1
vote
6answers
1k views
The Next Palindrome - reducing total execution time
I tried to solve one SPOJ problem. I wrote one program in Python, however, it got accepted by the SPOJ judges, but its total execution time is 2.88s. The same algorithm used in C language having ...
1
vote
1answer
473 views
Reverse and Add: find a palindrome
This is one of codeeval challenges
Challenge Description:
Credits: Programming Challenges by Steven S. Skiena and Miguel A.
Revilla
The problem is as follows: choose a number, reverse ...
