#!/usr/bin/ruby
# Cramer's rule, using the Matrix class
# https://rosettacode.org/wiki/Cramer%27s_rule
func cramers_rule(A, terms) {
    ^A -> map {|i|
        A.dclone.set_column(i, terms).det
    } »/» A.det
}
var matrix = Matrix(
    [2, -1,  5,  1],
    [3,  2,  2, -6],
    [1,  3,  3, -1],
    [5, -2, -3,  3],
)
var free_terms = [-3, -32, -47, 49]
assert_eq(cramers_rule(matrix, free_terms), [2, -12, -4, 1])
say "** Test passed!"