From f28b5b2f92719b6ae7ae7ceb90aa0ee4275ec97f Mon Sep 17 00:00:00 2001
From: dudaodong <lanliddd.2007@163.com>
Date: Fri, 1 Apr 2022 16:44:25 +0800
Subject: [PATCH] feat: add Minus func for set

---
 datastructure/set/set.go      | 13 +++++++++++++
 datastructure/set/set_test.go | 11 +++++++++++
 2 files changed, 24 insertions(+)

diff --git a/datastructure/set/set.go b/datastructure/set/set.go
index 57b1299..36bf254 100644
--- a/datastructure/set/set.go
+++ b/datastructure/set/set.go
@@ -103,3 +103,16 @@ func (s Set[T]) Intersection(other Set[T]) Set[T] {
 
 	return set
 }
+
+// Minus creates an set of whose element in origin set but not in compared set
+func (s Set[T]) Minus(comparedSet Set[T]) Set[T] {
+	set := NewSet[T]()
+
+	s.Iterate(func(value T) {
+		if !comparedSet.Contain(value) {
+			set.Add(value)
+		}
+	})
+
+	return set
+}
diff --git a/datastructure/set/set_test.go b/datastructure/set/set_test.go
index 3aa0e19..ceeb943 100644
--- a/datastructure/set/set_test.go
+++ b/datastructure/set/set_test.go
@@ -127,3 +127,14 @@ func TestSet_Intersection(t *testing.T) {
 
 	assert.Equal(expected, intersectionSet)
 }
+
+func TestSet_Minus(t *testing.T) {
+	assert := internal.NewAssert(t, "TestSet_Intersection")
+
+	set1 := NewSet(1, 2, 3)
+	set2 := NewSet(2, 3, 4, 5)
+	set3 := NewSet(2, 3)
+
+	assert.Equal(NewSet(1), set1.Minus(set2))
+	assert.Equal(NewSet(4, 5), set2.Minus(set3))
+}