Merge pull request #389 from openset/develop

Add: Power of Two

Author: Shuo

problems/power-of-two/power_of_two.go

@@ -1 +1,5 @@
 package power_of_two
+
+func isPowerOfTwo(n int) bool {
+	return n > 0 && n&(n-1) == 0
+}

problems/power-of-two/power_of_two_test.go

@@ -1 +1,39 @@
 package power_of_two
+
+import "testing"
+
+type caseType struct {
+	input    int
+	expected bool
+}
+
+func TestIsPowerOfTwo(t *testing.T) {
+	tests := [...]caseType{
+		{
+			input:    0,
+			expected: false,
+		},
+		{
+			input:    1,
+			expected: true,
+		},
+		{
+			input:    12,
+			expected: false,
+		},
+		{
+			input:    16,
+			expected: true,
+		},
+		{
+			input:    218,
+			expected: false,
+		},
+	}
+	for _, tc := range tests {
+		output := isPowerOfTwo(tc.input)
+		if output != tc.expected {
+			t.Fatalf("input: %v, output: %v, expected: %v", tc.input, output, tc.expected)
+		}
+	}
+}