[LEET-3340] add 3340

Author: fishercoder1534

paginated_contents/algorithms/4th_thousand/README.md

@@ -1,5 +1,6 @@
 | #    | Title                                                                                                                                                              | Solutions                                                                                                                         | Video                                                                         | Difficulty | Tag                                                                  
 |------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------|------------|----------------------------------------------------------------------
+| 3340 | [Check Balanced String](https://leetcode.com/problems/check-balanced-string/)                                                        | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3340.java) |                                                                               | Easy       |
 | 3330 | [Find the Original Typed String I](https://leetcode.com/problems/find-the-original-typed-string-i/)                                                        | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3330.java) |                                                                               | Easy       |
 | 3324 | [Find the Sequence of Strings Appeared on the Screen](https://leetcode.com/problems/find-the-sequence-of-strings-appeared-on-the-screen/)                                                        | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3324.java) |                                                                               | Easy       |
 | 3318 | [Find X-Sum of All K-Long Subarrays I](https://leetcode.com/problems/find-x-sum-of-all-k-long-subarrays-i/)                                                        | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3318.java) |                                                                               | Easy       |

src/main/java/com/fishercoder/solutions/fourththousand/_3340.java

@@ -0,0 +1,18 @@
+package com.fishercoder.solutions.fourththousand;
+
+public class _3340 {
+    public static class Solution1 {
+        public boolean isBalanced(String num) {
+            int oddSum = 0;
+            int evenSum = 0;
+            for (int i = 0; i < num.length(); i++) {
+                if (i % 2 == 0) {
+                    evenSum += Character.getNumericValue(num.charAt(i));
+                } else {
+                    oddSum += Character.getNumericValue(num.charAt(i));
+                }
+            }
+            return oddSum == evenSum;
+        }
+    }
+}