All Questions
8 questions
5
votes
3
answers
997
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 ...
3
votes
2
answers
1k
views
Counting the number of ways to decode a string
I am working on problem where I need to decode a string:
A message containing letters from A-Z is being encoded to numbers
using the following mapping:
'A' -> 1
'B' -> 2
...
'...
- 499
3
votes
2
answers
926
views
Memoized solution to Count number of ways to climb n steps
Problem statement : A Child is climbing up n steps with either 1 , 2, 3 hops ..how many ways can the child climb up the stairs?
source: cracking the coding interview book.
I have two solutions the ...
- 501
0
votes
2
answers
972
views
Number of Paths (BackTracking) in Java
Illustration
You're testing a new driverless car that is located at the Southwest
(bottom-left) corner of an n×n grid. The car is supposed to get to the
opposite, Northeast (top-right), corner ...
3
votes
1
answer
446
views
Find the maximum possible summation of differences of consecutive elements
Array A contains the elements, \$A_1,A_2, \ldots, A_N\$.
And array B contains the elements, \$B_1,B_2, \ldots, B_N\$.
There is a relationship between \$A_i\$ and \$B_i\$: any element \$A_i\$ ...
- 261
2
votes
1
answer
2k
views
Regular Expression Matching: Recursive and DP-based implementation
Problem Statement:
Implement regular expression matching with support for '.' and '*'.
'.' Matches any single character.
'*' Matches zero or more of the preceding element.
The matching ...
10
votes
2
answers
301
views
Undo format when format disappears
I was posed a question as follows:
Given a sentence like "John is a bad man", lets say all the formatting disappears and you are left with one string "johnisabadman". Given a dictionary of words, ...
- 1,213
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