From f7a31a2786674384e76054053b06792f7e557f1b Mon Sep 17 00:00:00 2001
From: Openset <openset@users.noreply.github.com>
Date: Thu, 24 Jan 2019 14:14:57 +0800
Subject: [PATCH] Add: Min Cost Climbing Stairs

---
 .../min_cost_climbing_stairs.go               | 16 ++++++++++++
 .../min_cost_climbing_stairs_test.go          | 26 +++++++++++++++++++
 2 files changed, 42 insertions(+)

diff --git a/problems/min-cost-climbing-stairs/min_cost_climbing_stairs.go b/problems/min-cost-climbing-stairs/min_cost_climbing_stairs.go
index 8364af07e..51d177876 100644
--- a/problems/min-cost-climbing-stairs/min_cost_climbing_stairs.go
+++ b/problems/min-cost-climbing-stairs/min_cost_climbing_stairs.go
@@ -1 +1,17 @@
 package min_cost_climbing_stairs
+
+func minCostClimbingStairs(cost []int) int {
+	f1, f2, l := 0, 0, len(cost)-1
+	for i := l; i >= 0; i-- {
+		f0 := f1
+		if f2 < f1 {
+			f0 = f2
+		}
+		f0 += cost[i]
+		f1, f2 = f0, f1
+	}
+	if f1 <= f2 {
+		return f1
+	}
+	return f2
+}
diff --git a/problems/min-cost-climbing-stairs/min_cost_climbing_stairs_test.go b/problems/min-cost-climbing-stairs/min_cost_climbing_stairs_test.go
index 8364af07e..877175e13 100644
--- a/problems/min-cost-climbing-stairs/min_cost_climbing_stairs_test.go
+++ b/problems/min-cost-climbing-stairs/min_cost_climbing_stairs_test.go
@@ -1 +1,27 @@
 package min_cost_climbing_stairs
+
+import "testing"
+
+type caseType struct {
+	input    []int
+	expected int
+}
+
+func TestMinCostClimbingStairs(t *testing.T) {
+	tests := [...]caseType{
+		{
+			input:    []int{10, 15, 20},
+			expected: 15,
+		},
+		{
+			input:    []int{1, 100, 1, 1, 1, 100, 1, 1, 100, 1},
+			expected: 6,
+		},
+	}
+	for _, tc := range tests {
+		output := minCostClimbingStairs(tc.input)
+		if output != tc.expected {
+			t.Fatalf("input: %v, output: %v, expected: %v", tc.input, output, tc.expected)
+		}
+	}
+}