Dynamic programming is an algorithmic technique for efficiently solving problems with a recursive structure containing many overlapping subproblems.
0
votes
1answer
19 views
Loading URLs via a case statement
I have the following code which loads in a URL based on the id of a user-clicked button. I'm looking to compress it down as much as possible, and make it more modular and reusable:
...
3
votes
2answers
127 views
High execution time of LCS length program in Python2
I was trying to solve the Longest Common Subsequence problem on a HackerRank exercise.
It's quite simple and straightforward, just print out the length of the LCS. I submitted this code:
...
2
votes
2answers
34 views
Find the best path amongst N random points
For an application with a graphical canvas, I want to generate N points. But then I want to link those points, and I want to find the best path through those points.
I wanted to use a dynamic ...
1
vote
1answer
55 views
Levenshtein distance with edit sequence and alignment in Java
I have this program that computes a Levenshtein distance of the two input strings, their edit sequence, and the alignment:
LevenshteinEditDistance.java:
...
4
votes
2answers
50 views
Number of ways to make change for an amount
Task
Write a program that, given the amount to make change for and a list of coins prints out how many different ways you can make change from the coins to STDOUT.
My approach
The number to make ...
2
votes
1answer
34 views
Optimally allocating a resource with time-varying demand and cost
I'm working on the following DP which finds the optimal way to allocate a resource. At each time step I can either allocate (0.2 resources) at cost C or not in which case the storage is reduced by the ...
2
votes
1answer
16 views
Auto registering class registry
I built this auto registering registry to look into a package and import all modules and register any classes that are a subclass of a base class. I use it as a registry for a model's choices in ...
4
votes
1answer
142 views
Finding the longest path, avoiding obstacles in a 2D plane
The Scenario
You are given a matrix of size m x n (width x height) with m*n spots where there are a few obstacles. Spots with obstacles are marked as 1, and those without are marked as 0. You can ...
0
votes
1answer
57 views
Longest contiguous Increasing Subset in java
I have tried to come up with a solution to the longest increasing subsequence problem.Can this solution be optimized further?
Example 1:
Input: {5,4,3,7,8,9,11}
Output: 3, 7, 8, 9, 11
Example 2:
...
2
votes
2answers
70 views
4
votes
5answers
229 views
Pass Triangle challenge
In order to solve this challenge:
Challenge Description
By starting at the top of the triangle and moving to adjacent numbers on the row below, the maximum total from top to bottom is 27.
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11
votes
2answers
109 views
Dynamic Programming: Fibonacci-like recurrence relation
This is a problem from my Introduction to Algorithms textbook.
Consider the infinite sequence of numbers An|n>0 = (1,1,3,4,8,11,...) defined recursively as follows.
$$
A_n = \left\{\begin{aligned}
...
4
votes
2answers
93 views
Optimal matrix chain multiplication in Java
Preliminaries
Given two matrices
$$
A = \begin{pmatrix}
a_{11} & a_{12} & \dots & a_{1q} \\
a_{21} & a_{22} & \dots & a_{2q} \\
\vdots & \vdots & \ddots & \vdots ...
2
votes
0answers
43 views
Recursive implementation of integer partition without re-arrangement
Problem: Integer partition without re-arrangement
Input: An arrangement S of nonnegative numbers {s1, . . . , sn} and an ...
8
votes
2answers
214 views
Quick Sum TopCoder (Brute Force solution)
Given a string of digits, find the minimum number of additions
required for the string to equal some target number. Each addition is
the equivalent of inserting a plus sign somewhere into the ...
11
votes
1answer
135 views
Counting paths in an n-dimensional grid that stay within the boundaries
Problem Statement
You are situated in an N dimensional grid at position (x1, x2, …, xN).
The dimensions of the grid are (D1, D2, …, DN). In one step, you can
walk one step ahead or behind in ...
0
votes
0answers
12 views
Time Complexity Analysis,Linear Sliding Window Algorithm Fails in SPOJ Aliens in a Train?
I need to find the largest interval with Value Less than a Limit Lt.
The Data is as Follows
For Every Test Case T
Number of elements N , limit Lt
N number of elements data
I wrote the ...
9
votes
3answers
298 views
Find the Nth number divisible by only 2,3,5, or 7
I recently participated in a small friendly competition and this was one of the questions:
A number whose only prime factors are 2, 3, 5 or 7 is called a humble
number. The first 20 humble ...
2
votes
1answer
54 views
Implementation of Longest Common Subsequence
So I implemented the LCS algorithm once using a 2-D matrix to store values while the other one used a python dictionary. I found the dictionary implementation was easier to implement and was a more ...
2
votes
0answers
85 views
Multiple 0-1 knapsack
I have a problem were the time in minutes of N songs are given and I have to write the maximum number of time in K CDs.
Input description
The first input line consists of two positive integers N ...
2
votes
1answer
52 views
Construct biggest stacked tower with restriction
Problem
The problem is to build the tallest tower made up of cylinders, respecting all the rules.
Will be arranged on the table, an amount of \$N\$ cylinders.
Each cylinder has one color: Red, ...
3
votes
1answer
213 views
Subset sum whose set contains only positive integers
I was trying to write a dynamic programming algorithm using a bottom up approach that solves the subset sum problem's version where the solution can be either an empty set and the initial set can only ...
5
votes
2answers
324 views
Finding the rod pieces in the rod cut issue
I have been reading the chapter 15 of "Introduction to Algorithms" (3rd edition) by Cormen, etc. The chapter 15 is about dynamic programming, and the first example they show us is the "rod cut ...
1
vote
1answer
175 views
LeetCode Minimum Path Sum algorithm
I am attempting to solve the Minimum Path Sum algorithm problem and I have a working solution, however there was an unwritten requirement that the algorithm not exceed an unspecified amount of time ...
4
votes
1answer
258 views
HackerRank - Candies
Here is the solution I've written for Hacker Rank Candies challenge.
It uses dynamic programming (memoization in a boxed array).
I'm interested on what could be done to improve this code in term of ...
3
votes
1answer
479 views
Calculating the sum of array elements to the left and right
I am using C++ to code the following logic:
An Array is given we have to traverse the array such that sum of array elements to its left must be equal to sum of elements to its right.
BTW this is ...
6
votes
3answers
123 views
ChessMetric - Topcoder Challenge
My solution for the topcoder ChessMetric challenge seems really slow. I feel like there should be a better way, but I'm not sure.
Challenge Description
Suppose you had an n by n chess board ...
4
votes
1answer
60 views
AvoidRoads - TopCoder Challenge
I'm learning Dynamic Programming, following the topcoder guide. I just solved the AvoidRoads challenge. It passes all the test cases, but I don't have much experience, so I don't know if it's good.
...
7
votes
2answers
113 views
Minimum number of coins problem using dynamic programming - follow up
I previously posted a code here. It turns out that the code is not following the correct dynamic programming principles and instead it was based on a greedy approach. Hence, I started again, keeping ...
10
votes
3answers
1k views
Coin Change: Minimum number of coins
Problem:
You are given n types of coin denominations of values \$v(1) < v(2) < ... < v(n)\$ (all integers). Assume \$v(1) = 1\$, so you can always make change for any amount of money ...
1
vote
2answers
114 views
BadNeighbors - Topcoder puzzle
I'm learning Dynamic Programming, following the topcoder guide. I just solved the BadNeighbors puzzle. It passes all the test cases, but I don't have much experience, so I don't know if it's good.
...
3
votes
3answers
48 views
Max contiguous slice in Ruby
I need to compute the max contiguous slice in an array. I wrote this function, but I am not sure if it is correct or I am missing edge cases. I ran several cases.
...
2
votes
1answer
478 views
Implementation of Sequence Alignment in C++
Below is my implementation of the dynamic programming solution to the sequence alignment problem in C++11:
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14
votes
5answers
985 views
DP example for “Power of Two” in Python
I'm not familiar with Python but want to provide a code snippet for an SO question about Dynamic Programming.
The snippet should show the bottom-up approach of DP.
The function ...
10
votes
1answer
317 views
House-coloring optimization challenge
I have an interview coming up in the next few weeks, and I'm choosing to be interviewed in Python. I began programming in Python (it was about four years ago), so the syntax is natural to me, but I ...
10
votes
2answers
217 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, ...
6
votes
1answer
226 views
Longest Increasing Subsequence
I am learning dynamic programming and I have written down some code for longest increasing subsequence. I would like to know if there is any case or any area of improvement in the terms of ...
6
votes
2answers
232 views
Counting Increasing Subsequences of size K recursive
The original description of the problem can be found here, its input here and its expected output here.
The problem:
Given a integer sequence a1 ... an (-10000
\$\leq\$ ai \$\leq\$ 10000). ...
3
votes
4answers
548 views
Find the minimum number of coins
I'm trying to learn dynamic programming and the most popular one is to find the minimum number of coins for the change. I come up with this but I just want to improve this code which I think it could ...
5
votes
1answer
53 views
Optimal way to annihilate a list by removing items from the ends
I'm stuck with a contest problem.
Description:
What is the minimum number of moves to annihilate an int array where the possible moves are:
Remove both the first and last elements if they are ...
4
votes
2answers
2k views
Finding all the subsets in an array of integers that sum to a given target
Problem Statement:
Given an Array if ints, Find out all the subsets in the Array that
sum to a given target value.
Example:
If the input array is:
...
5
votes
1answer
732 views
Minimum number of coins - (dynamic programming solution - topdown approach)
This is a problem from topcoder tutorials
Given a list of N coins, their values (V1, V2, ... , VN), and the total sum S. Find the minimum number of coins the sum of which is S (we can use as many ...
8
votes
1answer
156 views
Reading, processing and counting an array setting limits
Last weekend my teacher asked me to create code to solve a problem:
Giving a dynamic array, we want to pass the array elements from a file. The first number in the file N gives us the array ...
2
votes
1answer
611 views
Solving the rod-cutting problem using dynamic programming
I've written what I believe is a valid dynamic programming solution to a variation of the rod cutting problem. In this problem, the goal is to make as few cuts as possible on a rod of length n.
I ...
1
vote
0answers
476 views
DP algorithm to find minimum average wait for customer-serving system
Below is the code to find the minimum average waiting time for customers at a store. I want improve the time complexity of the code. As an overview of the logic, I start from ...
4
votes
1answer
234 views
Optimizing a dynamic programming solution for “Oil Well”
I'm trying to solve the Oil Well problem on Hackerrank using dynamic programming and it works. However, it times out for some of the test cases. I wanted to know how this program can be improved so ...
1
vote
1answer
404 views
Coin problem through brute force
I have some code that will brute force solve the following problem:
Given a set of x coins and a target sum to reach, what is the fewest number of coins required to reach that target?
The code ...
7
votes
1answer
1k 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 ...
3
votes
1answer
501 views
Calculate possible balances in piggy-bank by weight
I have solved Piggy-Bank problem on SPOJ using dynamic programming.
The question asks you to get the minimum value that is possible with given weight (\$w\$) and one or more coins (\$n\$) with given ...
5
votes
1answer
283 views
Word break problem with dynamic programming
This is the original question.
I have implemented it in both ways. If I enter the word "icecream", should I output "ice" "cream" and also "icecream", or just "ice" and "cream"?
Is this a good ...
