LongestCommonPrefix.java

LongestCommonPrefix 

import java.util.Scanner;
import java.util.Arrays;

public class LongestCommonPrefix {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        // Taking user input for number of strings
        System.out.print("Enter number of strings: ");
        int n = sc.nextInt();
        sc.nextLine(); // consume newline

        String[] strs = new String[n];
        System.out.println("Enter the strings one by one:");
        for (int i = 0; i < n; i++) {
            strs[i] = sc.nextLine();
        }

        // Call the function
        String result = longestCommonPrefix(strs);
        System.out.println("Longest Common Prefix: " + result);

        sc.close();
    }

    public static String longestCommonPrefix(String[] strs) {
        if (strs == null || strs.length == 0) {
            return "";
        }

        Arrays.sort(strs); // Sort the array

        String first = strs[0];
        String last = strs[strs.length - 1];

        int i = 0;
        while (i < first.length() && i < last.length() && first.charAt(i) == last.charAt(i)) {
            i++;
        }

        return first.substring(0, i);
    }
}