Add solution #3043

JoshCrozier · JoshCrozier · commit f1f4f70b5234 · 2025-06-06T23:21:02.000-05:00
diff --git a/README.md b/README.md
@@ -2146,6 +2146,7 @@
 3038|[Maximum Number of Operations With the Same Score I](./solutions/3038-maximum-number-of-operations-with-the-same-score-i.js)|Easy|
 3039|[Apply Operations to Make String Empty](./solutions/3039-apply-operations-to-make-string-empty.js)|Medium|
 3042|[Count Prefix and Suffix Pairs I](./solutions/3042-count-prefix-and-suffix-pairs-i.js)|Easy|
+3043|[Find the Length of the Longest Common Prefix](./solutions/3043-find-the-length-of-the-longest-common-prefix.js)|Medium|
 3066|[Minimum Operations to Exceed Threshold Value II](./solutions/3066-minimum-operations-to-exceed-threshold-value-ii.js)|Medium|
 3068|[Find the Maximum Sum of Node Values](./solutions/3068-find-the-maximum-sum-of-node-values.js)|Hard|
 3105|[Longest Strictly Increasing or Strictly Decreasing Subarray](./solutions/3105-longest-strictly-increasing-or-strictly-decreasing-subarray.js)|Easy|
diff --git a/solutions/3043-find-the-length-of-the-longest-common-prefix.js b/solutions/3043-find-the-length-of-the-longest-common-prefix.js
@@ -0,0 +1,50 @@
+/**
+ * 3043. Find the Length of the Longest Common Prefix
+ * https://leetcode.com/problems/find-the-length-of-the-longest-common-prefix/
+ * Difficulty: Medium
+ *
+ * You are given two arrays with positive integers arr1 and arr2.
+ *
+ * A prefix of a positive integer is an integer formed by one or more of its digits, starting
+ * from its leftmost digit. For example, 123 is a prefix of the integer 12345, while 234 is not.
+ *
+ * A common prefix of two integers a and b is an integer c, such that c is a prefix of both a
+ * and b. For example, 5655359 and 56554 have common prefixes 565 and 5655 while 1223 and 43456
+ * do not have a common prefix.
+ *
+ * You need to find the length of the longest common prefix between all pairs of integers (x, y)
+ * such that x belongs to arr1 and y belongs to arr2.
+ *
+ * Return the length of the longest common prefix among all pairs. If no common prefix exists
+ * among them, return 0.
+ */
+
+/**
+ * @param {number[]} arr1
+ * @param {number[]} arr2
+ * @return {number}
+ */
+var longestCommonPrefix = function(arr1, arr2) {
+  const prefixSet = new Set();
+  let result = 0;
+
+  for (const num of arr1) {
+    let prefix = num;
+    while (prefix > 0) {
+      prefixSet.add(prefix);
+      prefix = Math.floor(prefix / 10);
+    }
+  }
+
+  for (const num of arr2) {
+    let prefix = num;
+    while (prefix > 0) {
+      if (prefixSet.has(prefix)) {
+        result = Math.max(result, String(prefix).length);
+      }
+      prefix = Math.floor(prefix / 10);
+    }
+  }
+
+  return result;
+};
