[LEET-3280] add 3280

Author: fishercoder1534

Diff for: paginated_contents/algorithms/4th_thousand/README.md

@@ -7,6 +7,7 @@
 | 3300 | [Minimum Element After Replacement With Digit Sum](https://leetcode.com/problems/minimum-element-after-replacement-with-digit-sum/)                                        | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3300java)  |                                                                               | Easy       |
 | 3289 | [The Two Sneaky Numbers of Digitville](https://leetcode.com/problems/the-two-sneaky-numbers-of-digitville/)                                                                | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3289.java) |                                                                               | Easy       |
 | 3285 | [Find Indices of Stable Mountains](https://leetcode.com/problems/find-indices-of-stable-mountains/)                                                                | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3285.java) |                                                                               | Easy       |
+| 3280 | [Convert Date to Binary](https://leetcode.com/problems/convert-date-to-binary/)                                                                | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3280.java) |                                                                               | Easy       |
 | 3270 | [Find the Key of the Numbers](https://leetcode.com/problems/find-the-key-of-the-numbers/)                      | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3270.java) |                                                                               | Easy       |
 | 3264 | [Final Array State After K Multiplication Operations I](https://leetcode.com/problems/final-array-state-after-k-multiplication-operations-i/)                      | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3264.java) |                                                                               | Easy       |
 | 3263 | [Convert Doubly Linked List to Array I](https://leetcode.com/problems/convert-doubly-linked-list-to-array-i/)                                                      | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3263.java) |                                                                               | Easy       |

Diff for: src/main/java/com/fishercoder/solutions/fourththousand/_3280.java

@@ -0,0 +1,16 @@
+package com.fishercoder.solutions.fourththousand;
+
+public class _3280 {
+    public static class Solution1 {
+        public String convertDateToBinary(String date) {
+            String[] parts = date.split("-");
+            StringBuilder sb = new StringBuilder();
+            for (String part : parts) {
+                sb.append(Integer.toBinaryString(Integer.parseInt(part)));
+                sb.append("-");
+            }
+            sb.setLength(sb.length() - 1);
+            return sb.toString();
+        }
+    }
+}

Diff for: src/test/java/com/fishercoder/fourththousand/_3280Test.java

@@ -0,0 +1,21 @@
+package com.fishercoder.fourththousand;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import com.fishercoder.solutions.fourththousand._3280;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+public class _3280Test {
+    private _3280.Solution1 solution1;
+
+    @BeforeEach
+    public void setup() {
+        solution1 = new _3280.Solution1();
+    }
+
+    @Test
+    public void test1() {
+        assertEquals("100000100000-10-11101", solution1.convertDateToBinary("2080-02-29"));
+    }
+}