fix: fix resize bug in HashMap

datastructure/hashmap/hashmap.go

@@ -98,6 +98,8 @@ func (hm *HashMap) resize() {
 
 	tempTable := hm.table
 
+	hm.table = make([]*mapNode, hm.capacity)
+
 	for i := 0; i < len(tempTable); i++ {
 		node := tempTable[i]
 		if node == nil {

datastructure/hashmap/hashmap_test.go

@@ -19,6 +19,18 @@ func TestHashMap_PutAndGet(t *testing.T) {
 	assert.Equal(4, hm.Get("abc"))
 }
 
+func TestHashMap_Resize(t *testing.T) {
+	assert := internal.NewAssert(t, "TestHashMap_Resize")
+
+	hm := NewHashMapWithCapacity(3, 3)
+
+	for i := 0; i < 20; i++ {
+		hm.Put(i, 10)
+	}
+
+	assert.Equal(10, hm.Get(5))
+}
+
 func TestHashMap_Delete(t *testing.T) {
 	assert := internal.NewAssert(t, "TestHashMap_Delete")