Add solution #3406

JoshCrozier · JoshCrozier · commit 16f7fa795af3 · 2025-07-22T23:49:25.000-05:00
diff --git a/README.md b/README.md
@@ -2688,6 +2688,7 @@
 3402|[Minimum Operations to Make Columns Strictly Increasing](./solutions/3402-minimum-operations-to-make-columns-strictly-increasing.js)|Easy|
 3403|[Find the Lexicographically Largest String From the Box I](./solutions/3403-find-the-lexicographically-largest-string-from-the-box-i.js)|Medium|
 3405|[Count the Number of Arrays with K Matching Adjacent Elements](./solutions/3405-count-the-number-of-arrays-with-k-matching-adjacent-elements.js)|Hard|
+3406|[Find the Lexicographically Largest String From the Box II](./solutions/3406-find-the-lexicographically-largest-string-from-the-box-ii.js)|Hard|
 3423|[Maximum Difference Between Adjacent Elements in a Circular Array](./solutions/3423-maximum-difference-between-adjacent-elements-in-a-circular-array.js)|Easy|
 3439|[Reschedule Meetings for Maximum Free Time I](./solutions/3439-reschedule-meetings-for-maximum-free-time-i.js)|Medium|
 3440|[Reschedule Meetings for Maximum Free Time II](./solutions/3440-reschedule-meetings-for-maximum-free-time-ii.js)|Medium|
diff --git a/solutions/3406-find-the-lexicographically-largest-string-from-the-box-ii.js b/solutions/3406-find-the-lexicographically-largest-string-from-the-box-ii.js
@@ -0,0 +1,52 @@
+/**
+ * 3406. Find the Lexicographically Largest String From the Box II
+ * https://leetcode.com/problems/find-the-lexicographically-largest-string-from-the-box-ii/
+ * Difficulty: Hard
+ *
+ * You are given a string word, and an integer numFriends.
+ *
+ * Alice is organizing a game for her numFriends friends. There are multiple rounds in the game,
+ * where in each round:
+ * - word is split into numFriends non-empty strings, such that no previous round has had the
+ *   exact same split.
+ * - All the split words are put into a box.
+ *
+ * Find the lexicographically largest string from the box after all the rounds are finished.
+ *
+ * A string a is lexicographically smaller than a string b if in the first position where a
+ * and b differ, string a has a letter that appears earlier in the alphabet than the corresponding
+ * letter in b.
+ *
+ * If the first min(a.length, b.length) characters do not differ, then the shorter string is the
+ * lexicographically smaller one.
+ */
+
+/**
+ * @param {string} word
+ * @param {number} numFriends
+ * @return {string}
+ */
+var answerString = function(word, numFriends) {
+  if (numFriends === 1) return word;
+  const n = word.length;
+  const maxLength = n - numFriends + 1;
+
+  const pairs = [];
+  for (let i = 0; i < n - 1; i++) {
+    pairs.push(word[i] + word[i + 1]);
+  }
+  const maxPair = pairs.reduce((a, b) => a > b ? a : b);
+  let result = word[n - 1];
+  let index = -1;
+
+  while (index < n) {
+    index = word.indexOf(maxPair, index + 1);
+    if (index === -1) break;
+    const candidate = word.substring(index, index + maxLength);
+    if (candidate > result) {
+      result = candidate;
+    }
+  }
+
+  return result;
+};
