All Questions
15 questions
5
votes
3
answers
998
views
LeetCode 678: Valid Parenthesis String, Recursion memoization to DP
How can the following recursion + memoization code be converted into a tabulation format dynamic programming solution?
The code is working, but I want to improve it.
The challenge I am facing is ...
2
votes
3
answers
559
views
Recursive palindrome check
I'm trying to solve this which basically calls for a recursive palindrome check with some minor extra steps (Special characters and whitespace can be ignored). The test inputs' length can be 100000 ...
9
votes
4
answers
3k
views
"What is the maximum that Player 1 can win?"
This is a question that I encountered in one of the competitive coding tests. The question goes as follows:
A 2-player game is being played. There is a single pile of stones. Every stone has an ...
- 275
3
votes
2
answers
595
views
Find the longest sub string of a word after concatenation of given words array
An Array of N words is given. Each word consists of small letters ('a'-'z'). Our goal is to concatenate the words in such a way as to obtain a single word with longest possible substring composed of ...
- 31
2
votes
2
answers
6k
views
Find the minimum number of coin change
Description:
You are given coins of different denominations and a total amount of money amount. Write a function to compute the fewest number of coins that you need to make up that amount. If that ...
- 5,177
1
vote
1
answer
501
views
Reinterpreting a string, treating < as a backspace character
I've come up with a solution to this coding challenge using recursion. In summary, the input is a string where the < symbol represents a backspace (up to 1 ...
- 369
1
vote
1
answer
134
views
Count all possible attendance records with length n, which will be regarded as rewardable
Given a positive integer n, return the number of all possible attendance records with length n, which will be regarded as rewardable. The answer may be very large, return it after \$\mod 10^9 + 7\$.
...
- 261
11
votes
2
answers
457
views
You need to diversify your strings
Challenge:
Write a program which prints all the permutations of a string in alphabetical order.
Specifications:
Your program should accept a file as its first argument.
The file contains input ...
- 9,929
5
votes
3
answers
5k
views
Using recursion to count substrings (with exceptions to the rule) in Java
I am going through the CodingBat exercises for Java. Here is the one I have just finished:
Given a string, compute recursively the number of times lowercase hi ...
- 1,312
10
votes
1
answer
2k
views
Arranging 8 queens on an 8x8 board
Print all the ways of arranging eight queens on an 8x8 board. Rules:
Queens should not share the same row, column, of any diagonal.
Any comment on my solution?
I didn't write unit tests but I ...
- 743
2
votes
2
answers
3k
views
Given a digit sequence, print the possible decodings of the given digit sequence
Examples:
12 gives:
'AB' and 'L'
and
123 gives
'ABC', 'LC' and 'AW'
Here is my attempt:
...
- 133
7
votes
1
answer
528
views
An Army of Ones
I've been practicing using recursion lately and thought this was a case where it would prove really useful, is this good use or is there some superior non-recursive way to go about it?
Challenge:
...
- 9,929
5
votes
4
answers
5k
views
Digital root recursive function
Haven't any experience writing recursive functions.(Generally tend to avoid them - not sure if that's a negative). What do you think about the following?
This is also my first time using JUnit, I'd ...
- 9,929
10
votes
1
answer
4k
views
Project Euler #14 -- longest Collatz sequence
I was reading this question and realized that I didn't know Python well enough to critique the algorithm. So I wrote a Java solution instead, which is inappropriate for that question. Since there's ...
- 7,014
5
votes
1
answer
2k
views
Finding if there is a subset that sums to a target value from an array of integers
I came across this problem.
Problem Statement:
Given an array of ints, is it possible to choose a group of some of
the ...
- 872