Add: Remove Outermost Parentheses

problems/remove-outermost-parentheses/remove_outermost_parentheses.go

@@ -0,0 +1,16 @@
+package remove_outermost_parentheses
+
+func removeOuterParentheses(S string) string {
+	ans, n := make([]rune, 0, len(S)), 0
+	for _, c := range S {
+		if c == '(' {
+			n++
+		} else {
+			n--
+		}
+		if (c == '(' && n != 1) || (c == ')' && n != 0) {
+			ans = append(ans, c)
+		}
+	}
+	return string(ans)
+}

problems/remove-outermost-parentheses/remove_outermost_parentheses_test.go

@@ -0,0 +1,31 @@
+package remove_outermost_parentheses
+
+import "testing"
+
+type caseType struct {
+	input    string
+	expected string
+}
+
+func TestRemoveOuterParentheses(t *testing.T) {
+	tests := [...]caseType{
+		{
+			input:    "(()())(())",
+			expected: "()()()",
+		},
+		{
+			input:    "(()())(())(()(()))",
+			expected: "()()()()(())",
+		},
+		{
+			input:    "()()",
+			expected: "",
+		},
+	}
+	for _, tc := range tests {
+		output := removeOuterParentheses(tc.input)
+		if output != tc.expected {
+			t.Fatalf("input: %v, output: %v, expected: %v", tc.input, output, tc.expected)
+		}
+	}
+}