Solution #14 - Nishitha - 05/08/2025 - commit #4

Author: nishithadaryn

Problems/#14 - Longest Common Prefix - Easy/explanation.md

@@ -1,14 +1,22 @@
-# Problem: Longest Common Prefix
-## Language: C++
+# Leetcode Problem #14: Longest Common Prefix (Easy)
+
+## Problem 
+
+Given an array of strings `strs`, return the **longest common prefix** string amongst them.  
+If there is no common prefix, return an **empty string**.
 
 ---
 
-1. Start with the first string as the prefix.
-2. For each string in the array:
-   - Reduce the prefix by comparing it with the current string.
-   - Stop early if prefix becomes empty.
+## Approach
+
+- Start with the first string as the **initial prefix**.
+- Compare it with the next string:
+  - If the current string doesn't start with the prefix, **trim the prefix** by one character from the end.
+  - Repeat until it matches or becomes an empty string.
+- Continue this for all strings in the list.
 
 ---
 
 
 
+

Problems/#14 - Longest Common Prefix - Easy/solution.cpp

@@ -0,0 +1,27 @@
+// LeetCode #14 - Longest Common Prefix
+// Language: C++
+
+#include <string>
+#include <vector>
+
+using namespace std;
+
+class Solution {
+public:
+    string longestCommonPrefix(vector<string>& strs) {
+        if (strs.empty()) return "";
+
+        string prefix = strs[0];
+
+        for (int i = 1; i < strs.size(); ++i) {
+            int j = 0;
+            while (j < prefix.size() && j < strs[i].size() && prefix[j] == strs[i][j])
+                ++j;
+            prefix = prefix.substr(0, j);
+            if (prefix.empty()) return "";
+        }
+
+        return prefix;
+    }
+};
+