- Added the Number egypt_greedy(p/q) method.

Returns the array of denominators, such that `egypt_greedy(p/q).sum{|d| 1/d }` equals `p/q`.

Example:

	say egypt_greedy(9/10)      #=> [2, 3, 15]
	say egypt_greedy(5/121)     #=> [25, 757, 763309, 873960180913, 1527612795642093418846225]

lib/Sidef/Types/Number/Number.pm

@@ -8587,6 +8587,44 @@ package Sidef::Types::Number::Number {
         return ((bless \$q1), (bless \$q2));
     }
 
+    sub egypt_greedy {
+        my ($pq) = @_;
+
+        $pq = _any2mpq($$pq) // return undef;
+
+        my $n = Math::GMPz::Rmpz_init();
+        my $d = Math::GMPz::Rmpz_init();
+
+        Math::GMPq::Rmpq_get_num($n, $pq);
+        Math::GMPq::Rmpq_get_den($d, $pq);
+
+        my @list;
+
+        state $g = Math::GMPz::Rmpz_init_nobless();
+
+        while (Math::GMPz::Rmpz_cmp_ui($n, 1) != 0) {
+
+            my $x = Math::GMPz::Rmpz_init();
+            Math::GMPz::Rmpz_div($x, $d, $n);
+            Math::GMPz::Rmpz_add_ui($x, $x, 1);
+
+            push @list, $x;
+
+            Math::GMPz::Rmpz_mul($n, $n, $x);
+            Math::GMPz::Rmpz_sub($n, $n, $d);
+            Math::GMPz::Rmpz_mul($d, $d, $x);
+            Math::GMPz::Rmpz_gcd($g, $n, $d);
+
+            if (Math::GMPz::Rmpz_cmp_ui($g, 1) > 0) {
+                Math::GMPz::Rmpz_divexact($n, $n, $g);
+                Math::GMPz::Rmpz_divexact($d, $d, $g);
+            }
+        }
+
+        push @list, $d;
+        Sidef::Types::Array::Array->new([map { bless \$_ } @list]);
+    }
+
     sub dump {
         my ($x) = @_;
 

lib/Sidef/Types/Number/Number.pod

@@ -2960,6 +2960,19 @@ Aliases: I<exponential_divisors>
 
 =cut
 
+=head2 egypt_greedy
+
+    egypt_greedy(p/q)
+
+Greedy algorithm for Egyptian fraction expansion (also called the Fibonacci-Sylvester algorithm): at each step, extract the largest unit fraction less than the target and replace the target with the remainder.
+
+    say egypt_greedy(9/10)      #=> [2, 3, 15]
+    say egypt_greedy(5/121)     #=> [25, 757, 763309, 873960180913, 1527612795642093418846225]
+
+Returns the array of denominators, such that C<egypt_greedy(p/q).sum{|d| 1/d }> equals C<p/q>.
+
+=cut
+
 =head2 ei
 
     ei(x)

scripts/Tests/number_methods.sf

@@ -1526,4 +1526,10 @@ assert_eq([farey_neighbors(100, 89/99)], [80/89, 9/10])
 assert_eq([farey_neighbors(100, 50/79)], [31/49, 19/30])
 assert_eq([farey_neighbors(100, 19/30)], [50/79, 45/71])
 
+assert_eq(egypt_greedy(9/10), %n[2, 3, 15])
+assert_eq(egypt_greedy(5/121), %n[25, 757, 763309, 873960180913, 1527612795642093418846225])
+
+assert_eq(egypt_greedy(43/97).sum{.inv}, 43/97)
+assert_eq(egypt_greedy(97/43).sum{.inv}, 97/43)
+
 say "** Tests passed!"