2022-06-20 update: added "Largest Number After Digit Swaps by Parity"

Author: fartem

Diff for: src/main/java/com/smlnskgmail/jaman/leetcodejava/easy/LargestNumberAfterDigitSwapsByParity.java

@@ -0,0 +1,48 @@
+package com.smlnskgmail.jaman.leetcodejava.easy;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+// https://leetcode.com/problems/largest-number-after-digit-swaps-by-parity/
+public class LargestNumberAfterDigitSwapsByParity {
+
+    private int input;
+
+    public LargestNumberAfterDigitSwapsByParity(int input) {
+        this.input = input;
+    }
+
+    public int solution() {
+        List<Integer> odds = new ArrayList<>();
+        List<Integer> evens = new ArrayList<>();
+        int ref = input;
+        while (input > 0) {
+            int curr = input % 10;
+            if (curr % 2 != 0) {
+                odds.add(curr);
+            } else {
+                evens.add(curr);
+            }
+            input /= 10;
+        }
+        Collections.sort(odds);
+        Collections.sort(evens);
+        int pO = 0;
+        int pE = 0;
+        int result = 0;
+        int mul = 1;
+        while (ref > 0) {
+            int curr = ref % 10;
+            if (curr % 2 != 0) {
+                result = odds.get(pO++) * mul + result;
+            } else {
+                result = evens.get(pE++) * mul + result;
+            }
+            ref /= 10;
+            mul *= 10;
+        }
+        return result;
+    }
+
+}

Diff for: src/test/java/com/smlnskgmail/jaman/leetcodejava/easy/LargestNumberAfterDigitSwapsByParityTest.java

@@ -0,0 +1,17 @@
+package com.smlnskgmail.jaman.leetcodejava.easy;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class LargestNumberAfterDigitSwapsByParityTest {
+
+    @Test
+    public void defaultTest() {
+        assertEquals(
+                3412,
+                new LargestNumberAfterDigitSwapsByParity(1234).solution()
+        );
+    }
+
+}