From 2fe8df158fa1ec57711c5c27e2b523699f7b43eb Mon Sep 17 00:00:00 2001
From: alexchao26 <alexchaoo@gmail.com>
Date: Mon, 21 Dec 2020 18:35:12 -0500
Subject: [PATCH] added string and int set implementations

.
---
 data-structures/set/set.go      | 75 +++++++++++++++++++++++++++++++++
 data-structures/set/set_test.go | 54 ++++++++++++++++++++++++
 2 files changed, 129 insertions(+)
 create mode 100644 data-structures/set/set.go
 create mode 100644 data-structures/set/set_test.go

diff --git a/data-structures/set/set.go b/data-structures/set/set.go
new file mode 100644
index 0000000..7134021
--- /dev/null
+++ b/data-structures/set/set.go
@@ -0,0 +1,75 @@
+package set
+
+// StringSet maintains a deduped list of strings added to it
+type StringSet map[string]bool
+
+// NewStringSet initializes a set with the values form the input string slice
+func NewStringSet(stringSlice []string) StringSet {
+	set := StringSet{}
+	for _, v := range stringSlice {
+		set[v] = true
+	}
+	return set
+}
+
+// Has returns true if the value if found in the underlying set
+func (s StringSet) Has(val string) bool {
+	_, ok := s[val]
+	return ok
+}
+
+// Add a value to the set
+func (s StringSet) Add(val string) {
+	s[val] = true
+}
+
+// Remove a value from the set
+func (s StringSet) Remove(val string) {
+	delete(s, val)
+}
+
+// Keys returns a slice of all keys in the set
+func (s StringSet) Keys() []string {
+	var keys []string
+	for k := range s {
+		keys = append(keys, k)
+	}
+	return keys
+}
+
+// IntSet maintains a deduped list of strings added to it
+type IntSet map[int]bool
+
+// NewIntSet initializes a set with the values form the input int slice
+func NewIntSet(intSlice []int) IntSet {
+	set := IntSet{}
+	for _, v := range intSlice {
+		set[v] = true
+	}
+	return set
+}
+
+// Has returns true if the value if found in the underlying set
+func (s IntSet) Has(val int) bool {
+	_, ok := s[val]
+	return ok
+}
+
+// Add a value to the set
+func (s IntSet) Add(val int) {
+	s[val] = true
+}
+
+// Remove a value from the set
+func (s IntSet) Remove(val int) {
+	delete(s, val)
+}
+
+// Keys returns a slice of all keys in the set
+func (s IntSet) Keys() []int {
+	var keys []int
+	for k := range s {
+		keys = append(keys, k)
+	}
+	return keys
+}
diff --git a/data-structures/set/set_test.go b/data-structures/set/set_test.go
new file mode 100644
index 0000000..6cd8c1b
--- /dev/null
+++ b/data-structures/set/set_test.go
@@ -0,0 +1,54 @@
+package set_test
+
+import (
+	"reflect"
+	"sort"
+	"testing"
+
+	"github.com/alexchao26/advent-of-code-go/data-structures/set"
+)
+
+func TestIntSet(t *testing.T) {
+	tests := []struct {
+		valToAdd int
+		wantHas  []int
+	}{
+		{5, []int{5}},
+		{5, []int{5}},
+		{10, []int{5, 10}},
+		{20, []int{5, 10, 20}},
+		{20, []int{5, 10, 20}},
+		{2230, []int{5, 10, 20, 2230}},
+		{123, []int{5, 10, 20, 123, 2230}},
+	}
+
+	intSet := set.NewIntSet(nil)
+	for _, tt := range tests {
+		intSet.Add(tt.valToAdd)
+		for _, want := range tt.wantHas {
+			if !intSet.Has(want) {
+				t.Errorf("want IntSet.Has(%d) = true, got false", want)
+			}
+		}
+	}
+
+	got := intSet.Keys()
+	sort.Ints(got)
+	want := []int{5, 10, 20, 123, 2230}
+	if !reflect.DeepEqual(got, want) {
+		t.Errorf("want intSet.Keys() to be %v, got %v", want, got)
+	}
+
+	valsToRemove := []int{5, 10, 20, 123, 2230}
+	for _, tt := range valsToRemove {
+		intSet.Remove(tt)
+		if intSet.Has(tt) {
+			t.Errorf("want IntSet.Has(%d) = false, got true", tt)
+		}
+	}
+
+	got = intSet.Keys()
+	if len(got) != 0 {
+		t.Errorf("want zero-length slice after removing all keys, got %v", got)
+	}
+}