Problem 1889. Get ranking of a combination looking for speed.

I have the numbers pulled without replacement from the set [1 2 3 4 5 6 7 8 9 10 11 12 13]; They are then ordered from least to greatest.

So a selection of [3 2 9], [9 2 3] are both considered to be [2 3 9].

There are 286 unique selections possible. These can be ordered in lexicographic order:

Element   1 = [ 1  2  3]
Element   2 = [ 1  2  4]
Element   3 = [ 1  2  5]
Element   4 = [ 1  2  6]
Element   5 = [ 1  2  7]
Element   6 = [ 1  2  8]
Element   7 = [ 1  2  9]
Element   8 = [ 1  2 10]
Element   9 = [ 1  2 11]
Element  10 = [ 1  2 12]
Element  11 = [ 1  2 13]
Element  12 = [ 1  3  4]
Element  13 = [ 1  3  5]
Element  14 = [ 1  3  6]
Element  15 = [ 1  3  7]
...
Element 285 = [10 12 13]
Element 286 = [11 12 13]

Given the three ordered values as a row vector, return the element number.

The test suite only passes if it is faster that my reference code.

Solution Stats

47.89% Correct | 52.11% Incorrect
Last Solution submitted on Jun 08, 2024

Problem Comments

Solution Comments

Show comments

Problem Recent Solvers48

Suggested Problems

More from this Author51

Problem Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!