From 9584d0c13db6d4f4fd8dbcf22bd0e658f8796355 Mon Sep 17 00:00:00 2001
From: Openset <openset@users.noreply.github.com>
Date: Mon, 28 Jan 2019 18:40:05 +0800
Subject: [PATCH] Add: Climbing Stairs

---
 problems/climbing-stairs/climbing_stairs.go   | 11 +++++++
 .../climbing-stairs/climbing_stairs_test.go   | 30 +++++++++++++++++++
 2 files changed, 41 insertions(+)

diff --git a/problems/climbing-stairs/climbing_stairs.go b/problems/climbing-stairs/climbing_stairs.go
index f5cab39db..364aab98d 100644
--- a/problems/climbing-stairs/climbing_stairs.go
+++ b/problems/climbing-stairs/climbing_stairs.go
@@ -1 +1,12 @@
 package climbing_stairs
+
+func climbStairs(n int) int {
+	if n == 1 {
+		return 1
+	}
+	first, second := 1, 2
+	for i := 3; i <= n; i++ {
+		first, second = second, first+second
+	}
+	return second
+}
diff --git a/problems/climbing-stairs/climbing_stairs_test.go b/problems/climbing-stairs/climbing_stairs_test.go
index f5cab39db..cf254f45b 100644
--- a/problems/climbing-stairs/climbing_stairs_test.go
+++ b/problems/climbing-stairs/climbing_stairs_test.go
@@ -1 +1,31 @@
 package climbing_stairs
+
+import "testing"
+
+type caseType struct {
+	input    int
+	expected int
+}
+
+func TestClimbStairs(t *testing.T) {
+	tests := [...]caseType{
+		{
+			input:    1,
+			expected: 1,
+		},
+		{
+			input:    2,
+			expected: 2,
+		},
+		{
+			input:    3,
+			expected: 3,
+		},
+	}
+	for _, tc := range tests {
+		output := climbStairs(tc.input)
+		if output != tc.expected {
+			t.Fatalf("input: %v, output: %v, expected: %v", tc.input, output, tc.expected)
+		}
+	}
+}