Added tasks 3597-3600

Author: javadev

src/main/java/g3501_3600/s3597_partition_string/Solution.java

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+package g3501_3600.s3597_partition_string;
+
+// #Medium #2025_06_29_Time_27_ms_(99.70%)_Space_57.45_MB_(6.81%)
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Solution {
+    private static class Trie {
+        public Trie[] trie = new Trie[26];
+    }
+
+    public List<String> partitionString(String s) {
+        var trie = new Trie();
+        var res = new ArrayList<String>();
+        var node = trie;
+        for (int i = 0, j = 0; i < s.length() && j < s.length(); ) {
+            int idx = s.charAt(j) - 'a';
+            if (node.trie[idx] == null) {
+                res.add(s.substring(i, j + 1));
+                node.trie[idx] = new Trie();
+                i = j + 1;
+                j = i;
+                node = trie;
+                continue;
+            } else {
+                node = node.trie[idx];
+                j++;
+            }
+        }
+        return res;
+    }
+}

src/main/java/g3501_3600/s3597_partition_string/readme.md

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+3597\. Partition String
+
+Medium
+
+Given a string `s`, partition it into **unique segments** according to the following procedure:
+
+*   Start building a segment beginning at index 0.
+*   Continue extending the current segment character by character until the current segment has not been seen before.
+*   Once the segment is unique, add it to your list of segments, mark it as seen, and begin a new segment from the next index.
+*   Repeat until you reach the end of `s`.
+
+Return an array of strings `segments`, where `segments[i]` is the <code>i<sup>th</sup></code> segment created.
+
+**Example 1:**
+
+**Input:** s = "abbccccd"
+
+**Output:** ["a","b","bc","c","cc","d"]
+
+**Explanation:**
+
+Here is your table, converted from HTML to Markdown:
+
+| Index | Segment After Adding | Seen Segments         | Current Segment Seen Before? | New Segment | Updated Seen Segments            |
+|-------|----------------------|-----------------------|------------------------------|-------------|----------------------------------|
+| 0     | "a"                  | []                    | No                           | ""          | ["a"]                            |
+| 1     | "b"                  | ["a"]                 | No                           | ""          | ["a", "b"]                       |
+| 2     | "b"                  | ["a", "b"]            | Yes                          | "b"         | ["a", "b"]                       |
+| 3     | "bc"                 | ["a", "b"]            | No                           | ""          | ["a", "b", "bc"]                 |
+| 4     | "c"                  | ["a", "b", "bc"]      | No                           | ""          | ["a", "b", "bc", "c"]            |
+| 5     | "c"                  | ["a", "b", "bc", "c"] | Yes                          | "c"         | ["a", "b", "bc", "c"]            |
+| 6     | "cc"                 | ["a", "b", "bc", "c"] | No                           | ""          | ["a", "b", "bc", "c", "cc"]      |
+| 7     | "d"                  | ["a", "b", "bc", "c", "cc"] | No                     | ""          | ["a", "b", "bc", "c", "cc", "d"] |
+
+Hence, the final output is `["a", "b", "bc", "c", "cc", "d"]`.
+
+**Example 2:**
+
+**Input:** s = "aaaa"
+
+**Output:** ["a","aa"]
+
+**Explanation:**
+
+Here is your table converted to Markdown:
+
+| Index | Segment After Adding | Seen Segments | Current Segment Seen Before? | New Segment | Updated Seen Segments |
+|-------|----------------------|---------------|------------------------------|-------------|----------------------|
+| 0     | "a"                  | []            | No                           | ""          | ["a"]                |
+| 1     | "a"                  | ["a"]         | Yes                          | "a"         | ["a"]                |
+| 2     | "aa"                 | ["a"]         | No                           | ""          | ["a", "aa"]          |
+| 3     | "a"                  | ["a", "aa"]   | Yes                          | "a"         | ["a", "aa"]          |
+
+Hence, the final output is `["a", "aa"]`.
+
+**Constraints:**
+
+*   <code>1 <= s.length <= 10<sup>5</sup></code>
+*   `s` contains only lowercase English letters.

src/main/java/g3501_3600/s3598_longest_common_prefix_between_adjacent_strings_after_removals/Solution.java

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+package g3501_3600.s3598_longest_common_prefix_between_adjacent_strings_after_removals;
+
+// #Medium #2025_06_29_Time_28_ms_(74.57%)_Space_66.99_MB_(42.36%)
+
+public class Solution {
+    private int solve(String a, String b) {
+        int len = Math.min(a.length(), b.length());
+        int cnt = 0;
+        while (cnt < len && a.charAt(cnt) == b.charAt(cnt)) {
+            cnt++;
+        }
+        return cnt;
+    }
+
+    public int[] longestCommonPrefix(String[] words) {
+        int n = words.length;
+        int[] ans = new int[n];
+        if (n <= 1) {
+            return ans;
+        }
+        int[] lcp = new int[n - 1];
+        for (int i = 0; i + 1 < n; i++) {
+            lcp[i] = solve(words[i], words[i + 1]);
+        }
+        int[] prefmax = new int[n - 1];
+        int[] sufmax = new int[n - 1];
+        prefmax[0] = lcp[0];
+        for (int i = 1; i < n - 1; i++) {
+            prefmax[i] = Math.max(prefmax[i - 1], lcp[i]);
+        }
+        sufmax[n - 2] = lcp[n - 2];
+        for (int i = n - 3; i >= 0; i--) {
+            sufmax[i] = Math.max(sufmax[i + 1], lcp[i]);
+        }
+        for (int i = 0; i < n; i++) {
+            int best = 0;
+            if (i >= 2) {
+                best = Math.max(best, prefmax[i - 2]);
+            }
+            if (i + 1 <= n - 2) {
+                best = Math.max(best, sufmax[i + 1]);
+            }
+            if (i > 0 && i < n - 1) {
+                best = Math.max(best, solve(words[i - 1], words[i + 1]));
+            }
+            ans[i] = best;
+        }
+        return ans;
+    }
+}

src/main/java/g3501_3600/s3598_longest_common_prefix_between_adjacent_strings_after_removals/readme.md

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+3598\. Longest Common Prefix Between Adjacent Strings After Removals
+
+Medium
+
+You are given an array of strings `words`. For each index `i` in the range `[0, words.length - 1]`, perform the following steps:
+
+*   Remove the element at index `i` from the `words` array.
+*   Compute the **length** of the **longest common prefix** among all **adjacent** pairs in the modified array.
+
+Return an array `answer`, where `answer[i]` is the length of the longest common prefix between the adjacent pairs after removing the element at index `i`. If **no** adjacent pairs remain or if **none** share a common prefix, then `answer[i]` should be 0.
+
+**Example 1:**
+
+**Input:** words = ["jump","run","run","jump","run"]
+
+**Output:** [3,0,0,3,3]
+
+**Explanation:**
+
+*   Removing index 0:
+    *   `words` becomes `["run", "run", "jump", "run"]`
+    *   Longest adjacent pair is `["run", "run"]` having a common prefix `"run"` (length 3)
+*   Removing index 1:
+    *   `words` becomes `["jump", "run", "jump", "run"]`
+    *   No adjacent pairs share a common prefix (length 0)
+*   Removing index 2:
+    *   `words` becomes `["jump", "run", "jump", "run"]`
+    *   No adjacent pairs share a common prefix (length 0)
+*   Removing index 3:
+    *   `words` becomes `["jump", "run", "run", "run"]`
+    *   Longest adjacent pair is `["run", "run"]` having a common prefix `"run"` (length 3)
+*   Removing index 4:
+    *   words becomes `["jump", "run", "run", "jump"]`
+    *   Longest adjacent pair is `["run", "run"]` having a common prefix `"run"` (length 3)
+
+**Example 2:**
+
+**Input:** words = ["dog","racer","car"]
+
+**Output:** [0,0,0]
+
+**Explanation:**
+
+*   Removing any index results in an answer of 0.
+
+**Constraints:**
+
+*   <code>1 <= words.length <= 10<sup>5</sup></code>
+*   <code>1 <= words[i].length <= 10<sup>4</sup></code>
+*   `words[i]` consists of lowercase English letters.
+*   The sum of `words[i].length` is smaller than or equal <code>10<sup>5</sup></code>.

src/main/java/g3501_3600/s3599_partition_array_to_minimize_xor/Solution.java

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+package g3501_3600.s3599_partition_array_to_minimize_xor;
+
+// #Medium #2025_06_29_Time_141_ms_(89.34%)_Space_45.26_MB_(46.16%)
+
+import java.util.Arrays;
+
+public class Solution {
+    public int minXor(int[] nums, int k) {
+        int n = nums.length;
+        // Step 1: Prefix XOR array
+        int[] pfix = new int[n + 1];
+        for (int i = 1; i <= n; i++) {
+            pfix[i] = pfix[i - 1] ^ nums[i - 1];
+        }
+        // Step 2: DP table
+        int[][] dp = new int[n + 1][k + 1];
+        for (int[] row : dp) {
+            Arrays.fill(row, Integer.MAX_VALUE);
+        }
+        for (int i = 0; i <= n; i++) {
+            // Base case: 1 partition
+            dp[i][1] = pfix[i];
+        }
+        // Step 3: Fill DP for partitions 2 to k
+        for (int parts = 2; parts <= k; parts++) {
+            for (int end = parts; end <= n; end++) {
+                for (int split = parts - 1; split < end; split++) {
+                    int segmentXOR = pfix[end] ^ pfix[split];
+                    int maxXOR = Math.max(dp[split][parts - 1], segmentXOR);
+                    dp[end][parts] = Math.min(dp[end][parts], maxXOR);
+                }
+            }
+        }
+        return dp[n][k];
+    }
+}

src/main/java/g3501_3600/s3599_partition_array_to_minimize_xor/readme.md

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+3599\. Partition Array to Minimize XOR
+
+Medium
+
+You are given an integer array `nums` and an integer `k`.
+
+Your task is to partition `nums` into `k` non-empty ****non-empty subarrays****. For each subarray, compute the bitwise **XOR** of all its elements.
+
+Return the **minimum** possible value of the **maximum XOR** among these `k` subarrays.
+
+**Example 1:**
+
+**Input:** nums = [1,2,3], k = 2
+
+**Output:** 1
+
+**Explanation:**
+
+The optimal partition is `[1]` and `[2, 3]`.
+
+*   XOR of the first subarray is `1`.
+*   XOR of the second subarray is `2 XOR 3 = 1`.
+
+The maximum XOR among the subarrays is 1, which is the minimum possible.
+
+**Example 2:**
+
+**Input:** nums = [2,3,3,2], k = 3
+
+**Output:** 2
+
+**Explanation:**
+
+The optimal partition is `[2]`, `[3, 3]`, and `[2]`.
+
+*   XOR of the first subarray is `2`.
+*   XOR of the second subarray is `3 XOR 3 = 0`.
+*   XOR of the third subarray is `2`.
+
+The maximum XOR among the subarrays is 2, which is the minimum possible.
+
+**Example 3:**
+
+**Input:** nums = [1,1,2,3,1], k = 2
+
+**Output:** 0
+
+**Explanation:**
+
+The optimal partition is `[1, 1]` and `[2, 3, 1]`.
+
+*   XOR of the first subarray is `1 XOR 1 = 0`.
+*   XOR of the second subarray is `2 XOR 3 XOR 1 = 0`.
+
+The maximum XOR among the subarrays is 0, which is the minimum possible.
+
+**Constraints:**
+
+*   `1 <= nums.length <= 250`
+*   <code>1 <= nums[i] <= 10<sup>9</sup></code>
+*   `1 <= k <= n`