Questions tagged [dynamic-programming]

Dynamic programming is an algorithmic technique for efficiently solving problems with a recursive structure containing many overlapping subproblems.

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Why below recursive DP solution is so slow? (Leetcode Q# 123 - Best Time to Buy and Sell Stock III)

This is regarding leetcode Question# 123. I have solved the question (code below) but the solution is showing "Your runtime beats 5.89 % of cpp submissions."? Is there any additional ...
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65 views

Split money into every possible combination of coin denominations

Background and objective of the code Based on this Dev.to challenge, I wrote the Python code below (TIO link also available). The task was to return the least number of coins in a given denomination ...
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1answer
70 views

C++ Dynamic Array Class Testing

I'm creating a basic Dynamic Array class in C++, and I'd like to know if there are any bugs/memory leaks I haven't noticed yet. dyn_arr.h : ...
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1answer
51 views

Find sequence to a target number using restricted set of primitive operations

Given an integer 𝑛, compute the minimum number of operations(+1, x2, x3) needed to obtain the number 𝑛 starting from the number 1. I did this using this code: ...
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Knapsack performance issue

I'm solving a knapsack problem here. It works, but gives time limit exceeds on a certain test case. Problem statement There are N items, numbered 1,2,…,N. For each i (1≤i≤N), Item i has a weight of ...
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1answer
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LeetCode 375: Guess Number Higher or Lower II

I'm posting my C++ code for LeetCode's Guess Number Higher or Lower II. If you have time and would like to review, please do so. Problem We are playing the Guess Game. The game is as follows: I pick ...
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1answer
101 views

LeetCode 1320: Minimum Distance to Type a Word Using Two Fingers II

I'm posting my Python code for LeetCode's 1320. If you have time and would like to review, please do so. Problem You have a keyboard layout as shown above in the XY plane, where each English ...
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1answer
63 views

LeetCode 1320: Minimum Distance to Type a Word Using Two Fingers I

I'm posting my C++ code for LeetCode's 1320. If you have time and would like to review, please do so. Thank you! Problem You have a keyboard layout as shown above in the XY plane, where each English ...
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1answer
69 views

How can I use the State monad effectively in Haskell?

I have written a simple fibonacci function in Haskell that uses the State monad to save solutions to overlapping sub-problems. Now despite the function working I am not really happy with the solution, ...
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1answer
51 views

Maximum subset sum with no adjacent elements

Write a function that takes an array of integers (Both Positive and negative) and return the maximum sum of non adjacent elements. Note that even if all values are negative, I don't have an option to ...
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2answers
59 views

Recursive brute-force approach to maximum points you can obtain from cards

I came across this question on Leetcode. The question description is as follows: There are several cards arranged in a row, and each card has an associated number of points. The points are given in ...
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2answers
63 views

(Java) Read .txt and organize activities for hours / minutes

Doubts in logic to generate the output file according to the example I need that even if he reaches the total_min <720 condition he continues to travel the lines. 720 is the total number of minutes ...
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Matrix problem, the path that is the flattest

So in this problem I am given an NxN matrix, in which each value of the matrix represents an altitude. I need to find the best path from the top-left corner to the bottom-right one, my moves being ...
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1answer
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LeetCode: Trapping Rain Water DP C#

Please review for performance and C# style. I already solved this question in 1 way. LeetCode: trapping rain water C# I tried also the dynamic programming approch https://leetcode.com/problems/...
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C# - Reapply the manipulation of JS Object in .Net Core

IMPORTANT: I made another version with some improvements: Version 2 Since some months ago I disagree with the native/code methods to manipulate dynamic or ...
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1answer
67 views

Is there a route to the end of the jump table?

I'm currently learning about Dynamic Programming and solving a "coding question" related to the topic. Given an array of non-negative integers, you are initially positioned at the first ...
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1answer
110 views

Using Dynamic Programming to reduce time complexity

Input A long string of numbers, A list of numbers in string Output Minimum space needed in long string to match maximum numbers from list Example ...
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Dynamic programming knapsack solution

I wrote a solution to the Knapsack problem in Python, using a bottom-up dynamic programming algorithm. It correctly computes the optimal value, given a list of items with values and weights, and a ...
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596 views

LeetCode: Longest String Chain (Java)

For the question, I had a pretty messy solution so I would like some advice on how to better use Java to make the code a bit cleaner. Also, a semi-hack that I did that I'm not proud of is checking if ...
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1answer
43 views

Dynamic SQL query for count data

I'm working on an application that counts the number of employees in each department. Here's my code: ...
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1answer
88 views

Find the smallest number of perfect squares that sum to a target

Given a positive integer n, find the smallest number of perfect squares (for example, 1, 4, 9, 16, ...) that sum to n. ...
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A function to scan user input as string

I know that multiple functions are already available. However, I thought of writing my own because I wanted to learn the logic (and also because I thought there wasn't enough confusion :P). Please ...
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1answer
323 views

Printing the number of ways a message can be decoded

My below solution to the following problem is exceeding the maximum recursion depth. I am looking for any improvements which i can make. Problem Alice and Bob need to send secret messages to each ...
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1answer
150 views

Maximum sum combination

I am trying to solve this question: https://www.codechef.com/problems/TADELIVE Andy and Bob are the only two delivery men of Pizza-chef store. Today, the store received N orders. It's known that ...
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Total number of non overlapping subsets

I am trying to solve this question. The essence of the problem is this: Given a list of school classes with start and end times, find the total number of non-overlapping subsets. I've written up a ...
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666 views

Minimum path sum in a triangle (Project Euler 18 and 67) with Python

Project Euler 18 Project Euler 67 As problem 67 is harder, I'll go with that one: By starting at the top of the triangle below and moving to adjacent numbers on the row below, the maximum ...
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1answer
398 views

Snakes and Ladders using a magic die

This is a problem from here where you're given a magic die, and the objective is to find the minimum number of dice throws (hops) to go from the start point to the end of the board, and win the game. ...
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1answer
698 views

SPOJ - Alphacode, using dynamic programming

I am currently trying out a programming problem, SPOJ Alphacode, that involves dynamic programming. In an encoding system where A=1, B=2, …, Z=26, a message 25114 ...
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find longest common substring in space O(n)

I am working on the class question find the longest common substring from 2 strings but I would like to return the longest common substring instead of just size of longest common substring.like ...
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Rod Cutting Problem Code

I am learning dynamic programming. I read articles for the rod cutting problem and I applied it in cpp, and I got a doubt, does the below code solves the problem through memoization (say, previously ...
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How do I optimize memoization in order to find longest palindromic substring?

I want to find the longest palindromic substring using dynamic programming in Python3. The strings can be as large as this string. I have seen other questions on this problem that successfully solve ...
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212 views

LeetCode: House Robber III C#

https://leetcode.com/problems/house-robber-iii/ Please review for performance The thief has found himself a new place for his thievery again. There is only one entrance to this area, called the "...
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183 views

LeetCode: Shortest Common Supersequence C#

https://leetcode.com/problems/shortest-common-supersequence/ Given two strings str1 and str2, return the shortest string that has both str1 and str2 as subsequences. If multiple answers exist, ...
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1answer
224 views

Solution to knapsack problem exceeds time and RAM limits

My goal is to code the knapsack problem algorithm. The problem is that a knapsack has a given weight limit, W. I have a collection of items which have a given ...
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LeetCode: Burst Balloons C#

https://leetcode.com/problems/burst-balloons/ Given n balloons, indexed from 0 to n-1, ...
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Determine if a string is a sequence of dictionary words

This is Leetcode problem 139: "Wordbreak" Problem: Given a non-empty string s and a dictionary wordDict containing a list ...
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Recursion to dynamic programming [closed]

I was trying to solve a problem on de-arrangements (Number of partial derangement such that exactly prime number discs are found away from their natural positions? (Any number of non-prime K disks ...
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119 views

Project Euler #14: Longest Collatz Sequence starting point

Problem statement: The following iterative sequence is defined for the set of positive integers: n → n/2 (n is even) n → 3n + 1 (n is odd) Using the rule above and starting with 13, we ...
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Calculate the rates at which users get stuck at each stage

I completed an algorithm problem just as a personal study, and I can't help but feel like my solution is a bit needlessly complicated, although I can't figure out a better way to do it. Here's the ...
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2answers
661 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 ... ...
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1answer
71 views

Optimal BST challenge

I was coding the problem here. I think I have solved it, but I ran into time limit exceeded issues. I am new in Competitive Programming, so I was looking for a better, time efficient logic for solving ...
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1answer
124 views

Project Euler # 21 amicable numbers Python

Let \$d(n)\$ be defined as the sum of proper divisors of \$n\$ (numbers less than \$n\$ which divide evenly into \$n\$). If \$d(a) = b\$ and \$d(b) = a\$, where \$a ≠ b\$, then \$a\$ and \$b\$ are an ...
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Minimum cost path of matrix using Python

I was reading this article about finding the minimum cost path from (0,0) to any (m,n) point in a matrix. Using python the ...
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1answer
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Length of the longest common sub sequence bottom up

Could I get some feedback on this code? I included a test case as well. This code computes the longest common sub sequence given paired data, it was not part of any challenge I just did it to learn ...
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162 views

Optimal burger-eating challenge

Little history to give context to the problem: The Krusty-Burgers Homer Simpson is a smart guy who likes to eat Krusty-Burgers, and it takes m minutes for Homer ...
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1answer
177 views

The Dungeon game

This is a Leetcode problem - The demons had captured the princess (P) and imprisoned her in the bottom-right corner of a dungeon. The dungeon consists of M x N rooms laid out in a 2D grid. Our ...
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620 views

Python program to solve matrix-chain multiplication

An assignment at school required me to write a Python program for this task: In the matrix-chain multiplication problem, we are given a sequence of matrices ...
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0answers
189 views

Bursting Balloons

This is a Leetcode problem - Given n balloons, indexed from 0 to n-1. Each balloon is ...
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1answer
323 views

Python program to solve the “rod-cutting problem”

An assignment at school required me to write a program for this task: In the rod-cutting problem, we are given a rod of length n inches and a table of prices <...

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