Linked Questions

1
vote
0answers
108 views

how to prove correctness of this greedy algorithm? [duplicate]

I did exercise problem from Pittsburgh university cs department. homework. Question 8 is somewhat exciting. Q8 is solved using greedy algorithm but I have no idea how to prove. Below is Question. ...
3
votes
1answer
4k views

How does “Greedy Stays Ahead” Prove an Optimal Greedy Algorithm?

I have found many proofs online about proving that a greedy algorithm is optimal, specifically within the context of the interval scheduling problem. On the second page of Cornell's Greedy Stays ...
0
votes
3answers
740 views

Find longest path in graph with N nodes and N edges

We have given weighted undirected connected graph with $n$ nodes and $n$ edges, we want to find the longest path in it. Note that the path should be in each node at most once. Since the graph has $n$ ...
1
vote
1answer
907 views

Does a greedy strategy exist for this instance of the Bin Packing Problem?

I was wondering whether I can solve the following problem by using a greedy strategy: Let's say that I have a set of containers with 2 dimensions (width and height) and a set of items also with 2 ...
2
votes
0answers
1k views

Why is it necessary to sort according to the starting time in the interval partitioning problem?

What is the problem if we sort the intervals according to their finishing time like the interval scheduling problem? Could someone give a counterexample ? Note- (refer here for detailed definition) ...
3
votes
1answer
821 views

How to prove a greedy algorithm that uses the longest increasing subsequence?

Here is the thing, I am solving an problem, and I think, say, I am pretty sure that I have the correct algorithm but I haven't been able to prove it because of my lack of practice prooving greedy ...
3
votes
4answers
138 views

How to select best k fractions out of n fractions (k<=n) so as to have (numerator sum / denominator sum) maximum?

For example, given 4 fractions $\frac{4}{2}$, $\frac{2}{3}$, $\frac{1}{2}$, $\frac{10}{20}$, I have to select 3 fractions out of these 4 so that the value of $\frac{\text{numerator sum}}{\text{...
1
vote
1answer
475 views

Proof of a greedy algorithm concerning “Buy and Resell Problem”

"Buy and Resell Problem" can be described in the following way: There are $n$ cities. For each city, the price of products in this city is given (a positive number). Now a person will travel from ...
0
votes
1answer
592 views

Is my proof of my greedy algorithm to find subsequence correct?

Credit to KleinBerg and Taros Book Some of your friends have gotten into the burgeoning field of time-series data mining, in which one looks for patterns in sequences of events that occur over time. ...
3
votes
1answer
295 views

Minimal date interval cover algorithm

The problem involves date intervals filtered by days of week. For example, the filtered interval {2001 APR 1 - 2001 APR 30, 17} corresponds to all Mondays and Sundays between April 1 and April 30. ...
0
votes
1answer
450 views

Vertex Cover special cases

This was from a test from my university: Consider $T = t_1, t_2, \cdots, t_n$ a set of intervals of the form $(s, e)$, representing the start and end time, respectively. Now, select the minimum ...
1
vote
1answer
199 views

Why this greedy algorithm does not return the optimal solution to this NP-hard problem?

Problem: In the generalized assignment problem with unit-value items, there are $m$ bins of capacity $C$ each. There are $n$ items where each item $i$ has weight $w_{ij}$ with bin $j$. The objective ...
1
vote
0answers
313 views

With restrictions, can the knapsack puzzle be solved with a greedy algorithm?

I know that with the knapsack problem in general, there is no known greedy algorithm to solve it. But, say we add the following constraints: • All items have values equal to their weights (for all $...
0
votes
1answer
177 views

Cards shuffling. Greedy algorithm

We have n deck of cards. To shuffle i-th deck we need a(i) seconds. Our task is to give a greedy algorithm, which will merge two decks until we have one deck. My idea is to create a priority queue. ...
2
votes
1answer
187 views

Greedy algorithm for even item distribution

I have this problem where I need to design a greedy algorithm. The problem is as follows: A chocolate factory owns $n$ stores, which are connected by a single road. Each store has a limited supply $...

15 30 50 per page