Add: Number of Recent Calls

problems/number-of-recent-calls/number_of_recent_calls.go

@@ -1 +1,25 @@
 package number_of_recent_calls
+
+import "container/list"
+
+type RecentCounter struct {
+	queue *list.List
+}
+
+func Constructor() RecentCounter {
+	return RecentCounter{list.New()}
+}
+
+func (this *RecentCounter) Ping(t int) int {
+	this.queue.PushBack(t)
+	for this.queue.Front().Value.(int) < t-3000 {
+		this.queue.Remove(this.queue.Front())
+	}
+	return this.queue.Len()
+}
+
+/**
+ * Your RecentCounter object will be instantiated and called as such:
+ * obj := Constructor();
+ * param_1 := obj.Ping(t);
+ */

problems/number-of-recent-calls/number_of_recent_calls_test.go

@@ -1 +1,29 @@
 package number_of_recent_calls
+
+import (
+	"reflect"
+	"testing"
+)
+
+type caseType struct {
+	input    []int
+	expected []int
+}
+
+func TestConstructor(t *testing.T) {
+	tests := [...]caseType{
+		{
+			input:    []int{1, 100, 3001, 3002},
+			expected: []int{1, 2, 3, 3},
+		},
+	}
+	for _, tc := range tests {
+		obj, output := Constructor(), make([]int, 0)
+		for _, t := range tc.input {
+			output = append(output, obj.Ping(t))
+		}
+		if !reflect.DeepEqual(output, tc.expected) {
+			t.Fatalf("input: %v, output: %v, expected: %v", tc.input, output, tc.expected)
+		}
+	}
+}