Add: Height Checker

problems/height-checker/height_checker.go

@@ -0,0 +1,15 @@
+package height_checker
+
+import "sort"
+
+func heightChecker(heights []int) int {
+	ans, dst := 0, make([]int, len(heights))
+	copy(dst, heights)
+	sort.Ints(dst)
+	for i, v := range dst {
+		if heights[i] != v {
+			ans++
+		}
+	}
+	return ans
+}

problems/height-checker/height_checker_test.go

@@ -0,0 +1,23 @@
+package height_checker
+
+import "testing"
+
+type caseType struct {
+	input    []int
+	expected int
+}
+
+func TestHeightChecker(t *testing.T) {
+	tests := [...]caseType{
+		{
+			input:    []int{1, 1, 4, 2, 1, 3},
+			expected: 3,
+		},
+	}
+	for _, tc := range tests {
+		output := heightChecker(tc.input)
+		if output != tc.expected {
+			t.Fatalf("input: %v, output: %v, expected: %v", tc.input, output, tc.expected)
+		}
+	}
+}