subset_sum


subset_sum, a MATLAB code which seeks solutions of the subset sum problem, in which it is desired to find a subset of integers which has a given sum.

SUBSET_SUM_TABLE works by a kind of dynamic programming approach, constructing a table of all possible sums from 1 to S. The storage required is N * S, so for large S this can be an issue.

SUBSET_SUM_FIND works by brute force, trying every possible subset to see if it sums to the desired value. It uses the bits of a 32 bit integer to keep track of the possibilities, and hence cannot work with more N = 31 weights.

Licensing:

The computer code and data files made available on this web page are distributed under the MIT license

Languages:

subset_sum is available in a C version and a C++ version and a Fortran90 version and a MATLAB version and an Octave version and a Python version.

Related Data and Programs:

subset_sum_test

change_diophantine, a MATLAB code which sets up a Diophantine equation to solve the change making problem, which counts the number of ways a given sum can be formed using coins of various denominations.

change_dynamic, a MATLAB code which uses dynamic programming to solve the change making problem, which counts the number of ways a given sum can be formed using coins of various denominations.

change_greedy, a MATLAB code which uses the greedy method to seek a solution to the change making problem, which tries to match a given amount by selecting coins of various denominations.

change_polynomial, a MATLAB code which uses a polynomial multiplication algorithm to count the ways of making various sums using a given number of coins.

combo, a MATLAB code which includes many combinatorial routines.

knapsack_01_brute, a MATLAB code which uses brute force to solve small versions of the 0/1 knapsack problem;

knapsack_dynamic, a MATLAB code which uses dynamic programming to solve a knapsack problem.

knapsack_greedy, a MATLAB code which uses a greedy algorithm to estimate a solution of the knapsack problem;

mcnuggets, a MATLAB code which counts M(N), the number of ways a given number N of Chicken McNuggets can be assembled, given that they are only available in packages of 6, 9, and 20.

mcnuggets_diophantine, a MATLAB code which uses Diophantine methods to find the ways a given number N of Chicken McNuggets can be assembled, given that they are only available in packages of 6, 9, and 20.

partition_brute, a MATLAB code which uses brute force to seek solutions of the partition problem, splitting a set of integers into two subsets with equal sum.

partition_greedy, a MATLAB code which uses a greedy algorithm to seek a solution of the partition problem, in which a given set of integers is to be split into two groups whose sums are as close as possible.

satisfy_brute, a MATLAB code which uses brute force to find all assignments of values to a set of logical variables which make a complicated logical statement true.

subset_sum_backtrack, a MATLAB code which uses backtracking to solve the subset sum problem, to find a subset of a set of integers which has a given sum.

subset_sum_brute, a MATLAB code which uses brute force to solve the subset sum problem, to find a subset of a set of integers which has a given sum.

tsp_brute, a MATLAB code which reads a file of city-to-city distances and solves the traveling salesperson problem, using brute force.

tsp_descent, a MATLAB code which is given a city-to-city distance map, chooses an initial tour at random, and then tries a number of simple variations, seeking to quickly find a tour of lower cost.

tsp_greedy, a MATLAB code which reads a file of city-to-city distances, picks a starting city, and then successively visits the nearest unvisited city.

tsp_random, a MATLAB code which reads a file of city-to-city distances, and then randomly samples a number of possible tours, to quickly seek a tour of lower length.

Reference:

  1. Alexander Dewdney,
    The Turing Omnibus,
    Freeman, 1989,
    ISBN13: 9780716781547,
    LC: QA76.D45.
  2. Donald Kreher, Douglas Simpson,
    Combinatorial Algorithms,
    CRC Press, 1998,
    ISBN: 0-8493-3988-X,
    LC: QA164.K73.
  3. Silvano Martello, Paolo Toth,
    Knapsack Problems: Algorithms and Computer Implementations,
    Wiley, 1990,
    ISBN: 0-471-92420-2,
    LC: QA267.7.M37.

Source Code:


Last modified on 12 March 2019.