Valid Parentheses - s의 길이가 홀수인 경우 early return

Author: forest000014

valid-parentheses/forest000014.java

@@ -9,6 +9,10 @@ class Solution {
     public boolean isValid(String s) {
         Stack<Character> st = new Stack<>();
 
+        if (s.length() % 2 == 1) {
+            return false;
+        }
+
         for (char ch : s.toCharArray()) {
             if (ch == '(' || ch == '{' || ch == '[') {
                 st.push(ch);