diff --git a/src/main/kotlin/g3701_3800/s3731_find_missing_elements/Solution.kt b/src/main/kotlin/g3701_3800/s3731_find_missing_elements/Solution.kt
new file mode 100644
index 00000000..799091fe
--- /dev/null
+++ b/src/main/kotlin/g3701_3800/s3731_find_missing_elements/Solution.kt
@@ -0,0 +1,29 @@
+package g3701_3800.s3731_find_missing_elements
+
+// #Easy #Array #Hash_Table #Sorting #Weekly_Contest_474
+// #2025_11_05_Time_2_ms_(100.00%)_Space_46.48_MB_(84.44%)
+
+class Solution {
+    fun findMissingElements(nums: IntArray): List<Int> {
+        var maxi = 0
+        var mini = 101
+        val list: MutableList<Int> = ArrayList()
+        val array = BooleanArray(101)
+        for (num in nums) {
+            array[num] = true
+            if (maxi < num) {
+                maxi = num
+            }
+            if (mini > num) {
+                mini = num
+            }
+        }
+        for (index in mini + 1..<maxi) {
+            if (array[index]) {
+                continue
+            }
+            list.add(index)
+        }
+        return list
+    }
+}
diff --git a/src/main/kotlin/g3701_3800/s3731_find_missing_elements/readme.md b/src/main/kotlin/g3701_3800/s3731_find_missing_elements/readme.md
new file mode 100644
index 00000000..e48870f9
--- /dev/null
+++ b/src/main/kotlin/g3701_3800/s3731_find_missing_elements/readme.md
@@ -0,0 +1,46 @@
+3731\. Find Missing Elements
+
+Easy
+
+You are given an integer array `nums` consisting of **unique** integers.
+
+Originally, `nums` contained **every integer** within a certain range. However, some integers might have gone **missing** from the array.
+
+The **smallest** and **largest** integers of the original range are still present in `nums`.
+
+Return a **sorted** list of all the missing integers in this range. If no integers are missing, return an **empty** list.
+
+**Example 1:**
+
+**Input:** nums = [1,4,2,5]
+
+**Output:** [3]
+
+**Explanation:**
+
+The smallest integer is 1 and the largest is 5, so the full range should be `[1,2,3,4,5]`. Among these, only 3 is missing.
+
+**Example 2:**
+
+**Input:** nums = [7,8,6,9]
+
+**Output:** []
+
+**Explanation:**
+
+The smallest integer is 6 and the largest is 9, so the full range is `[6,7,8,9]`. All integers are already present, so no integer is missing.
+
+**Example 3:**
+
+**Input:** nums = [5,1]
+
+**Output:** [2,3,4]
+
+**Explanation:**
+
+The smallest integer is 1 and the largest is 5, so the full range should be `[1,2,3,4,5]`. The missing integers are 2, 3, and 4.
+
+**Constraints:**
+
+*   `2 <= nums.length <= 100`
+*   `1 <= nums[i] <= 100`
\ No newline at end of file
diff --git a/src/main/kotlin/g3701_3800/s3732_maximum_product_of_three_elements_after_one_replacement/Solution.kt b/src/main/kotlin/g3701_3800/s3732_maximum_product_of_three_elements_after_one_replacement/Solution.kt
new file mode 100644
index 00000000..f507fdfc
--- /dev/null
+++ b/src/main/kotlin/g3701_3800/s3732_maximum_product_of_three_elements_after_one_replacement/Solution.kt
@@ -0,0 +1,23 @@
+package g3701_3800.s3732_maximum_product_of_three_elements_after_one_replacement
+
+// #Medium #Array #Math #Sorting #Greedy #Weekly_Contest_474
+// #2025_11_05_Time_6_ms_(88.00%)_Space_74.51_MB_(84.00%)
+
+import kotlin.math.abs
+
+class Solution {
+    fun maxProduct(nums: IntArray): Long {
+        var a: Long = 0
+        var b: Long = 0
+        for (x in nums) {
+            val ax = abs(x).toLong()
+            if (ax >= a) {
+                b = a
+                a = ax
+            } else if (ax > b) {
+                b = ax
+            }
+        }
+        return 100000L * a * b
+    }
+}
diff --git a/src/main/kotlin/g3701_3800/s3732_maximum_product_of_three_elements_after_one_replacement/readme.md b/src/main/kotlin/g3701_3800/s3732_maximum_product_of_three_elements_after_one_replacement/readme.md
new file mode 100644
index 00000000..48ad50d9
--- /dev/null
+++ b/src/main/kotlin/g3701_3800/s3732_maximum_product_of_three_elements_after_one_replacement/readme.md
@@ -0,0 +1,51 @@
+3732\. Maximum Product of Three Elements After One Replacement
+
+Medium
+
+You are given an integer array `nums`.
+
+You **must** replace **exactly one** element in the array with **any** integer value in the range <code>[-10<sup>5</sup>, 10<sup>5</sup>]</code> (inclusive).
+
+After performing this single replacement, determine the **maximum possible product** of **any three** elements at **distinct indices** from the modified array.
+
+Return an integer denoting the **maximum product** achievable.
+
+**Example 1:**
+
+**Input:** nums = [-5,7,0]
+
+**Output:** 3500000
+
+**Explanation:**
+
+Replacing 0 with -10<sup>5</sup> gives the array <code>[-5, 7, -10<sup>5</sup>]</code>, which has a product <code>(-5) * 7 * (-10<sup>5</sup>) = 3500000</code>. The maximum product is 3500000.
+
+**Example 2:**
+
+**Input:** nums = [-4,-2,-1,-3]
+
+**Output:** 1200000
+
+**Explanation:**
+
+Two ways to achieve the maximum product include:
+
+*   `[-4, -2, -3]` → replace -2 with 10<sup>5</sup> → product = <code>(-4) * 10<sup>5</sup> * (-3) = 1200000</code>.
+*   `[-4, -1, -3]` → replace -1 with 10<sup>5</sup> → product = <code>(-4) * 10<sup>5</sup> * (-3) = 1200000</code>.
+
+The maximum product is 1200000.
+
+**Example 3:**
+
+**Input:** nums = [0,10,0]
+
+**Output:** 0
+
+**Explanation:**
+
+There is no way to replace an element with another integer and not have a 0 in the array. Hence, the product of all three elements will always be 0, and the maximum product is 0.
+
+**Constraints:**
+
+*   <code>3 <= nums.length <= 10<sup>5</sup></code>
+*   <code>-10<sup>5</sup> <= nums[i] <= 10<sup>5</sup></code>
\ No newline at end of file
diff --git a/src/main/kotlin/g3701_3800/s3733_minimum_time_to_complete_all_deliveries/Solution.kt b/src/main/kotlin/g3701_3800/s3733_minimum_time_to_complete_all_deliveries/Solution.kt
new file mode 100644
index 00000000..35aa3448
--- /dev/null
+++ b/src/main/kotlin/g3701_3800/s3733_minimum_time_to_complete_all_deliveries/Solution.kt
@@ -0,0 +1,49 @@
+package g3701_3800.s3733_minimum_time_to_complete_all_deliveries
+
+// #Medium #Math #Binary_Search #Weekly_Contest_474
+// #2025_11_05_Time_2_ms_(100.00%)_Space_42.47_MB_(100.00%)
+
+import kotlin.math.max
+
+class Solution {
+    private fun pos(k: Long, n1: Long, n2: Long, p1: Int, p2: Int, lVal: Long): Boolean {
+        val kP1 = k / p1
+        val kP2 = k / p2
+        val kL = k / lVal
+        val s1 = kP2 - kL
+        val s2 = kP1 - kL
+        val sB = k - kP1 - kP2 + kL
+        val w1 = max(0L, n1 - s1)
+        val w2 = max(0L, n2 - s2)
+        return (w1 + w2) <= sB
+    }
+
+    private fun findGcd(a: Long, b: Long): Long {
+        if (b == 0L) {
+            return a
+        }
+        return findGcd(b, a % b)
+    }
+
+    fun minimumTime(d: IntArray, r: IntArray): Long {
+        val n1 = d[0].toLong()
+        val n2 = d[1].toLong()
+        val p1 = r[0]
+        val p2 = r[1]
+        val g = findGcd(p1.toLong(), p2.toLong())
+        val l = p1.toLong() * p2 / g
+        var lo = n1 + n2
+        var hi = (n1 + n2) * max(p1, p2)
+        var res = hi
+        while (lo <= hi) {
+            val mid = lo + (hi - lo) / 2
+            if (pos(mid, n1, n2, p1, p2, l)) {
+                res = mid
+                hi = mid - 1
+            } else {
+                lo = mid + 1
+            }
+        }
+        return res
+    }
+}
diff --git a/src/main/kotlin/g3701_3800/s3733_minimum_time_to_complete_all_deliveries/readme.md b/src/main/kotlin/g3701_3800/s3733_minimum_time_to_complete_all_deliveries/readme.md
new file mode 100644
index 00000000..4fbcff72
--- /dev/null
+++ b/src/main/kotlin/g3701_3800/s3733_minimum_time_to_complete_all_deliveries/readme.md
@@ -0,0 +1,53 @@
+3733\. Minimum Time to Complete All Deliveries
+
+Medium
+
+You are given two integer arrays of size 2: <code>d = [d<sub>1</sub>, d<sub>2</sub>]</code> and <code>r = [r<sub>1</sub>, r<sub>2</sub>]</code>.
+
+Two delivery drones are tasked with completing a specific number of deliveries. Drone `i` must complete <code>d<sub>i</sub></code> deliveries.
+
+Each delivery takes **exactly** one hour and **only one** drone can make a delivery at any given hour.
+
+Additionally, both drones require recharging at specific intervals during which they cannot make deliveries. Drone `i` must recharge every <code>r<sub>i</sub></code> hours (i.e. at hours that are multiples of <code>r<sub>i</sub></code>).
+
+Return an integer denoting the **minimum** total time (in hours) required to complete all deliveries.
+
+**Example 1:**
+
+**Input:** d = [3,1], r = [2,3]
+
+**Output:** 5
+
+**Explanation:**
+
+*   The first drone delivers at hours 1, 3, 5 (recharges at hours 2, 4).
+*   The second drone delivers at hour 2 (recharges at hour 3).
+
+**Example 2:**
+
+**Input:** d = [1,3], r = [2,2]
+
+**Output:** 7
+
+**Explanation:**
+
+*   The first drone delivers at hour 3 (recharges at hours 2, 4, 6).
+*   The second drone delivers at hours 1, 5, 7 (recharges at hours 2, 4, 6).
+
+**Example 3:**
+
+**Input:** d = [2,1], r = [3,4]
+
+**Output:** 3
+
+**Explanation:**
+
+*   The first drone delivers at hours 1, 2 (recharges at hour 3).
+*   The second drone delivers at hour 3.
+
+**Constraints:**
+
+*   <code>d = [d<sub>1</sub>, d<sub>2</sub>]</code>
+*   <code>1 <= d<sub>i</sub> <= 10<sup>9</sup></code>
+*   <code>r = [r<sub>1</sub>, r<sub>2</sub>]</code>
+*   <code>2 <= r<sub>i</sub> <= 3 * 10<sup>4</sup></code>
\ No newline at end of file
diff --git a/src/main/kotlin/g3701_3800/s3734_lexicographically_smallest_palindromic_permutation_greater_than_target/Solution.kt b/src/main/kotlin/g3701_3800/s3734_lexicographically_smallest_palindromic_permutation_greater_than_target/Solution.kt
new file mode 100644
index 00000000..2728cdde
--- /dev/null
+++ b/src/main/kotlin/g3701_3800/s3734_lexicographically_smallest_palindromic_permutation_greater_than_target/Solution.kt
@@ -0,0 +1,94 @@
+package g3701_3800.s3734_lexicographically_smallest_palindromic_permutation_greater_than_target
+
+// #Hard #String #Two_Pointers #Enumeration #Weekly_Contest_474
+// #2025_11_05_Time_4_ms_(100.00%)_Space_46.12_MB_(77.78%)
+
+class Solution {
+    internal fun func(i: Int, target: String, ans: CharArray, l: Int, r: Int, freq: IntArray, end: Boolean): Boolean {
+        if (l > r) {
+            return String(ans).compareTo(target) > 0
+        }
+        if (l == r) {
+            var left = '#'
+            for (k in 0 until 26) {
+                if (freq[k] > 0) {
+                    left = (k + 'a'.code).toChar()
+                }
+            }
+            freq[left.code - 'a'.code]--
+            ans[l] = left
+            if (func(i + 1, target, ans, l + 1, r - 1, freq, end)) {
+                return true
+            }
+            freq[left.code - 'a'.code]++
+            ans[l] = '#'
+            return false
+        }
+        if (end) {
+            for (j in 0 until 26) {
+                if (freq[j] > 1) {
+                    freq[j] -= 2
+                    val charJ = (j + 'a'.code).toChar()
+                    ans[l] = charJ
+                    ans[r] = charJ
+                    if (func(i + 1, target, ans, l + 1, r - 1, freq, end)) {
+                        return true
+                    }
+                    ans[l] = '#'
+                    ans[r] = '#'
+                    freq[j] += 2
+                }
+            }
+            return false
+        }
+        val curr = target[i]
+        var next = '1'
+        for (k in (curr.code - 'a'.code + 1) until 26) {
+            if (freq[k] > 1) {
+                next = (k + 'a'.code).toChar()
+                break
+            }
+        }
+        if (freq[curr.code - 'a'.code] > 1) {
+            ans[l] = curr
+            ans[r] = curr
+            freq[curr.code - 'a'.code] -= 2
+            if (func(i + 1, target, ans, l + 1, r - 1, freq, false)) { // end = false
+                return true
+            }
+            freq[curr.code - 'a'.code] += 2
+        }
+        if (next != '1') {
+            ans[l] = next
+            ans[r] = next
+            freq[next.code - 'a'.code] -= 2
+            if (func(i + 1, target, ans, l + 1, r - 1, freq, true)) { // end = true
+                return true
+            }
+        }
+        ans[l] = '#'
+        ans[r] = '#'
+        return false
+    }
+
+    fun lexPalindromicPermutation(s: String, target: String): String {
+        val freq = IntArray(26)
+        for (char in s) {
+            freq[char.code - 'a'.code]++
+        }
+        var oddc = 0
+        for (i in 0 until 26) {
+            if (freq[i] % 2 == 1) {
+                oddc++
+            }
+        }
+        if (oddc > 1) {
+            return ""
+        }
+        val ans = CharArray(s.length) { '#' }
+        if (func(0, target, ans, 0, s.length - 1, freq, false)) {
+            return String(ans)
+        }
+        return ""
+    }
+}
diff --git a/src/main/kotlin/g3701_3800/s3734_lexicographically_smallest_palindromic_permutation_greater_than_target/readme.md b/src/main/kotlin/g3701_3800/s3734_lexicographically_smallest_palindromic_permutation_greater_than_target/readme.md
new file mode 100644
index 00000000..fbf7ec28
--- /dev/null
+++ b/src/main/kotlin/g3701_3800/s3734_lexicographically_smallest_palindromic_permutation_greater_than_target/readme.md
@@ -0,0 +1,55 @@
+3734\. Lexicographically Smallest Palindromic Permutation Greater Than Target
+
+Hard
+
+You are given two strings `s` and `target`, each of length `n`, consisting of lowercase English letters.
+
+Return the **lexicographically smallest string** that is **both** a **palindromic permutation** of `s` and **strictly** greater than `target`. If no such permutation exists, return an empty string.
+
+**Example 1:**
+
+**Input:** s = "baba", target = "abba"
+
+**Output:** "baab"
+
+**Explanation:**
+
+*   The palindromic permutations of `s` (in lexicographical order) are `"abba"` and `"baab"`.
+*   The lexicographically smallest permutation that is strictly greater than `target` is `"baab"`.
+
+**Example 2:**
+
+**Input:** s = "baba", target = "bbaa"
+
+**Output:** ""
+
+**Explanation:**
+
+*   The palindromic permutations of `s` (in lexicographical order) are `"abba"` and `"baab"`.
+*   None of them is lexicographically strictly greater than `target`. Therefore, the answer is `""`.
+
+**Example 3:**
+
+**Input:** s = "abc", target = "abb"
+
+**Output:** ""
+
+**Explanation:**
+
+`s` has no palindromic permutations. Therefore, the answer is `""`.
+
+**Example 4:**
+
+**Input:** s = "aac", target = "abb"
+
+**Output:** "aca"
+
+**Explanation:**
+
+*   The only palindromic permutation of `s` is `"aca"`.
+*   `"aca"` is strictly greater than `target`. Therefore, the answer is `"aca"`.
+
+**Constraints:**
+
+*   `1 <= n == s.length == target.length <= 300`
+*   `s` and `target` consist of only lowercase English letters.
\ No newline at end of file
diff --git a/src/test/kotlin/g3701_3800/s3731_find_missing_elements/SolutionTest.kt b/src/test/kotlin/g3701_3800/s3731_find_missing_elements/SolutionTest.kt
new file mode 100644
index 00000000..1053f307
--- /dev/null
+++ b/src/test/kotlin/g3701_3800/s3731_find_missing_elements/SolutionTest.kt
@@ -0,0 +1,31 @@
+package g3701_3800.s3731_find_missing_elements
+
+import org.hamcrest.CoreMatchers.equalTo
+import org.hamcrest.MatcherAssert.assertThat
+import org.junit.jupiter.api.Test
+
+internal class SolutionTest {
+    @Test
+    fun findMissingElements() {
+        assertThat<List<Int>>(
+            Solution().findMissingElements(intArrayOf(1, 4, 2, 5)),
+            equalTo<List<Int>>(mutableListOf<Int>(3)),
+        )
+    }
+
+    @Test
+    fun findMissingElements2() {
+        assertThat<List<Int>>(
+            Solution().findMissingElements(intArrayOf(7, 8, 6, 9)),
+            equalTo<List<Int>>(mutableListOf<Int>()),
+        )
+    }
+
+    @Test
+    fun findMissingElements3() {
+        assertThat<List<Int>>(
+            Solution().findMissingElements(intArrayOf(5, 1)),
+            equalTo<List<Int>>(mutableListOf<Int>(2, 3, 4)),
+        )
+    }
+}
diff --git a/src/test/kotlin/g3701_3800/s3732_maximum_product_of_three_elements_after_one_replacement/SolutionTest.kt b/src/test/kotlin/g3701_3800/s3732_maximum_product_of_three_elements_after_one_replacement/SolutionTest.kt
new file mode 100644
index 00000000..7269907e
--- /dev/null
+++ b/src/test/kotlin/g3701_3800/s3732_maximum_product_of_three_elements_after_one_replacement/SolutionTest.kt
@@ -0,0 +1,28 @@
+package g3701_3800.s3732_maximum_product_of_three_elements_after_one_replacement
+
+import org.hamcrest.CoreMatchers.equalTo
+import org.hamcrest.MatcherAssert.assertThat
+import org.junit.jupiter.api.Test
+
+internal class SolutionTest {
+    @Test
+    fun maxProduct() {
+        assertThat<Long>(
+            Solution().maxProduct(intArrayOf(-5, 7, 0)),
+            equalTo<Long>(3500000L),
+        )
+    }
+
+    @Test
+    fun maxProduct2() {
+        assertThat<Long>(
+            Solution().maxProduct(intArrayOf(-4, -2, -1, -3)),
+            equalTo<Long>(1200000L),
+        )
+    }
+
+    @Test
+    fun maxProduct3() {
+        assertThat<Long>(Solution().maxProduct(intArrayOf(0, 10, 0)), equalTo<Long>(0L))
+    }
+}
diff --git a/src/test/kotlin/g3701_3800/s3733_minimum_time_to_complete_all_deliveries/SolutionTest.kt b/src/test/kotlin/g3701_3800/s3733_minimum_time_to_complete_all_deliveries/SolutionTest.kt
new file mode 100644
index 00000000..ad9dfc07
--- /dev/null
+++ b/src/test/kotlin/g3701_3800/s3733_minimum_time_to_complete_all_deliveries/SolutionTest.kt
@@ -0,0 +1,31 @@
+package g3701_3800.s3733_minimum_time_to_complete_all_deliveries
+
+import org.hamcrest.CoreMatchers.equalTo
+import org.hamcrest.MatcherAssert.assertThat
+import org.junit.jupiter.api.Test
+
+internal class SolutionTest {
+    @Test
+    fun minimumTime() {
+        assertThat<Long>(
+            Solution().minimumTime(intArrayOf(3, 1), intArrayOf(2, 3)),
+            equalTo<Long>(5L),
+        )
+    }
+
+    @Test
+    fun minimumTime2() {
+        assertThat<Long>(
+            Solution().minimumTime(intArrayOf(1, 3), intArrayOf(2, 2)),
+            equalTo<Long>(7L),
+        )
+    }
+
+    @Test
+    fun minimumTime3() {
+        assertThat<Long>(
+            Solution().minimumTime(intArrayOf(2, 1), intArrayOf(3, 4)),
+            equalTo<Long>(3L),
+        )
+    }
+}
diff --git a/src/test/kotlin/g3701_3800/s3734_lexicographically_smallest_palindromic_permutation_greater_than_target/SolutionTest.kt b/src/test/kotlin/g3701_3800/s3734_lexicographically_smallest_palindromic_permutation_greater_than_target/SolutionTest.kt
new file mode 100644
index 00000000..7d52f275
--- /dev/null
+++ b/src/test/kotlin/g3701_3800/s3734_lexicographically_smallest_palindromic_permutation_greater_than_target/SolutionTest.kt
@@ -0,0 +1,336 @@
+package g3701_3800.s3734_lexicographically_smallest_palindromic_permutation_greater_than_target
+
+import org.hamcrest.CoreMatchers.equalTo
+import org.hamcrest.MatcherAssert.assertThat
+import org.hamcrest.Matchers.allOf
+import org.hamcrest.Matchers.anyOf
+import org.hamcrest.Matchers.containsString
+import org.hamcrest.Matchers.greaterThanOrEqualTo
+import org.hamcrest.Matchers.hasLength
+import org.hamcrest.Matchers.not
+import org.hamcrest.Matchers.nullValue
+import org.junit.jupiter.api.Test
+
+internal class SolutionTest {
+    @Test
+    fun lexPalindromicPermutation() {
+        assertThat<String>(
+            Solution().lexPalindromicPermutation("baba", "abba"),
+            equalTo<String>("baab"),
+        )
+    }
+
+    @Test
+    fun lexPalindromicPermutation2() {
+        assertThat<String>(
+            Solution().lexPalindromicPermutation("baba", "bbaa"),
+            equalTo<String>(""),
+        )
+    }
+
+    @Test
+    fun lexPalindromicPermutation3() {
+        assertThat<String>(
+            Solution().lexPalindromicPermutation("abc", "abb"),
+            equalTo<String>(""),
+        )
+    }
+
+    @Test
+    fun lexPalindromicPermutation4() {
+        assertThat<String>(
+            Solution().lexPalindromicPermutation("aac", "abb"),
+            equalTo<String>("aca"),
+        )
+    }
+
+    @Test
+    fun lexPalindromicPermutation5() {
+        // Branch: oddc > 1
+        val result = Solution().lexPalindromicPermutation("abc", "a")
+        assertThat<String>(result, equalTo<String>(""))
+    }
+
+    @Test
+    fun lexPalindromicPermutation6() {
+        // Branch: oddc = 1
+        val result = Solution().lexPalindromicPermutation("aab", "a")
+        assertThat<String>(
+            result,
+            allOf<String>(not<String>(equalTo<String>("")), hasLength(3)),
+        )
+    }
+
+    @Test
+    fun lexPalindromicPermutation7() {
+        // Branch: oddc = 0
+        val result = Solution().lexPalindromicPermutation("aabb", "ab")
+        assertThat<String>(result, not<String>(equalTo<String>("")))
+    }
+
+    @Test
+    fun lexPalindromicPermutation8() {
+        // Branch: func returns false
+        val result = Solution().lexPalindromicPermutation("abc", "xyz")
+        assertThat<String>(result, equalTo<String>(""))
+    }
+
+    @Test
+    fun lexPalindromicPermutation9() {
+        // Edge case: length = 1
+        val result = Solution().lexPalindromicPermutation("a", "a")
+        assertThat<String>(result, equalTo<String>(""))
+    }
+
+    @Test
+    fun lexPalindromicPermutation10() {
+        // Branch: l > r and comparison result > 0
+        val target = "a"
+        val freq = IntArray(26)
+        val ans = charArrayOf('b', 'b')
+
+        val result = Solution().func(0, target, ans, 1, 0, freq, false)
+        assertThat<Boolean>(result, equalTo<Boolean>(true))
+    }
+
+    @Test
+    fun lexPalindromicPermutation11() {
+        // Branch: l > r and comparison result <= 0
+        val target = "z"
+        val freq = IntArray(26)
+        val ans = charArrayOf('a', 'a')
+
+        val result = Solution().func(0, target, ans, 1, 0, freq, false)
+        assertThat<Boolean>(result, equalTo<Boolean>(false))
+    }
+
+    @Test
+    fun lexPalindromicPermutation12() {
+        // Branch: l == r with available character
+        val target = "a"
+        val freq = IntArray(26)
+        // 'a' has frequency 1
+        freq[0] = 1
+        val ans = CharArray(1)
+
+        val result = Solution().func(0, target, ans, 0, 0, freq, false)
+        assertThat<Boolean>(result, equalTo<Boolean>(false))
+        assertThat<Char>(ans[0], equalTo<Char>('#'))
+    }
+
+    @Test
+    fun lexPalindromicPermutation13() {
+        // Branch: end = true, finds char with freq > 1
+        val target = "ab"
+        val freq = IntArray(26)
+        // 'a' can form a pair
+        freq[0] = 2
+        freq[1] = 0
+        val ans = CharArray(2)
+
+        val result = Solution().func(1, target, ans, 0, 1, freq, true)
+        assertThat<Boolean>(
+            result,
+            anyOf<Boolean>(equalTo<Boolean>(true), equalTo<Boolean>(false)),
+        )
+        // Frequency restored
+        assertThat<Int>(freq[0], equalTo<Int>(2))
+    }
+
+    @Test
+    fun lexPalindromicPermutation14() {
+        // Branch: end = true, no char has freq > 1
+        val target = "ab"
+        val freq = IntArray(26)
+        freq[0] = 1
+        freq[1] = 1
+        val ans = CharArray(2)
+
+        val result = Solution().func(1, target, ans, 0, 1, freq, true)
+        assertThat<Boolean>(result, equalTo<Boolean>(false))
+    }
+
+    @Test
+    fun lexPalindromicPermutation15() {
+        // Branch: end = true, tries different pairs
+        val target = "abc"
+        val freq = IntArray(26)
+        freq[0] = 2
+        freq[1] = 2
+        freq[2] = 2
+        val ans = CharArray(3)
+
+        Solution().func(1, target, ans, 0, 2, freq, true)
+        assertThat<Int>(freq[0], equalTo<Int>(0))
+        assertThat<Int>(freq[1], equalTo<Int>(2))
+        assertThat<Int>(freq[2], equalTo<Int>(1))
+    }
+
+    @Test
+    fun lexPalindromicPermutation16() {
+        // Branch: end = false, curr has freq > 1
+        val target = "a"
+        val freq = IntArray(26)
+        freq[0] = 2
+        val ans = CharArray(2)
+
+        Solution().func(0, target, ans, 0, 1, freq, false)
+        assertThat<Int>(freq[0], equalTo<Int>(0))
+    }
+
+    @Test
+    fun lexPalindromicPermutation17() {
+        // Branch: end = false, curr has freq <= 1
+        val target = "a"
+        val freq = IntArray(26)
+        freq[0] = 0
+        val ans = CharArray(2)
+
+        Solution().func(0, target, ans, 0, 1, freq, false)
+        assertThat<Int>(freq[0], equalTo<Int>(0))
+    }
+
+    @Test
+    fun lexPalindromicPermutation18() {
+        // Branch: end = false, finds next char with freq > 1
+        val target = "a"
+        val freq = IntArray(26)
+        freq[0] = 0
+        freq[1] = 2
+        val ans = CharArray(2)
+
+        Solution().func(0, target, ans, 0, 1, freq, false)
+        assertThat<Int>(freq[0], equalTo<Int>(0))
+        assertThat<Int>(freq[1], equalTo<Int>(0))
+    }
+
+    @Test
+    fun lexPalindromicPermutation19() {
+        // Branch: end = false, no next char with freq > 1
+        val target = "z"
+        val freq = IntArray(26)
+        freq[25] = 1
+        val ans = CharArray(2)
+
+        val result = Solution().func(0, target, ans, 0, 1, freq, false)
+        assertThat<Boolean>(result, equalTo<Boolean>(false))
+    }
+
+    @Test
+    fun lexPalindromicPermutation20() {
+        // Branch: end = false transitions to end = true
+        val target = "ab"
+        val freq = IntArray(26)
+        freq[0] = 2
+        freq[1] = 2
+        val ans = CharArray(2)
+
+        Solution().func(0, target, ans, 0, 1, freq, false)
+
+        assertThat<Int>(freq[0], equalTo<Int>(2))
+        assertThat<Int>(freq[1], equalTo<Int>(0))
+    }
+
+    @Test
+    fun lexPalindromicPermutation21() {
+        // Verify result is always a palindrome
+        val result = Solution().lexPalindromicPermutation("aabbcc", "abc")
+        if (!result.isEmpty()) {
+            val reversed = StringBuilder(result).reverse().toString()
+            assertThat<String>(result, equalTo<String>(reversed))
+        }
+    }
+
+    @Test
+    fun lexPalindromicPermutation22() {
+        // Verify character frequencies are preserved
+        val input = "aabbcc"
+        val result = Solution().lexPalindromicPermutation(input, "abc")
+
+        if (!result.isEmpty()) {
+            val inputFreq = IntArray(26)
+            val resultFreq = IntArray(26)
+
+            for (c in input.toCharArray()) {
+                inputFreq[c.code - 'a'.code]++
+            }
+            for (c in result.toCharArray()) {
+                resultFreq[c.code - 'a'.code]++
+            }
+
+            assertThat<IntArray>(resultFreq, equalTo<IntArray>(inputFreq))
+        }
+    }
+
+    @Test
+    fun lexPalindromicPermutation23() {
+        // Result length should match input length
+        val input = "aabbccdd"
+        val result = Solution().lexPalindromicPermutation(input, "abcd")
+
+        if (!result.isEmpty()) {
+            assertThat<Int>(result.length, equalTo<Int>(input.length))
+        }
+    }
+
+    @Test
+    fun lexPalindromicPermutation24() {
+        // Result should be >= target in lexicographical order
+        val result = Solution().lexPalindromicPermutation("aabbcc", "abc")
+
+        if (!result.isEmpty()) {
+            assertThat<Int>(result.compareTo("abc"), greaterThanOrEqualTo<Int>(0))
+        }
+    }
+
+    @Test
+    fun lexPalindromicPermutation25() {
+        // Complex scenario with multiple characters
+        val result = Solution().lexPalindromicPermutation("aabbccdd", "abcd")
+
+        assertThat<String>(
+            result,
+            anyOf<String>(
+                equalTo<String>(""),
+                allOf<String>(
+                    hasLength(8),
+                    containsString("a"),
+                    containsString("b"),
+                ),
+            ),
+        )
+    }
+
+    @Test
+    fun lexPalindromicPermutation26() {
+        // Edge case: empty string (if applicable)
+        val result = Solution().lexPalindromicPermutation("", "")
+        assertThat<String>(
+            result,
+            anyOf<String>(equalTo<String>(""), not<Any>(nullValue())),
+        )
+    }
+
+    @Test
+    fun lexPalindromicPermutation27() {
+        // Verify frequency array is restored after recursion
+        val target = "aabb"
+        val freq = IntArray(26)
+        val freqCopy: IntArray = freq.clone()
+
+        val ans = CharArray(4)
+        Solution().func(0, target, ans, 0, 3, freq, false)
+
+        assertThat<IntArray>(freq, equalTo<IntArray>(freqCopy))
+    }
+
+    @Test
+    fun lexPalindromicPermutation28() {
+        // Verify char array is properly initialized
+        val result = Solution().lexPalindromicPermutation("aa", "a")
+
+        if (!result.isEmpty()) {
+            assertThat<String>(result, not<String>(containsString("#")))
+        }
+    }
+}