Solution.java

import java.util.Scanner;

public class LCS {
    public static void findLCS(String str1, String str2) {
        int len1 = str1.length(), len2 = str2.length();
        int[][] dp = new int[len1 + 1][len2 + 1];

        for (int i = 1; i <= len1; i++) {
            for (int j = 1; j <= len2; j++) {
                if (str1.charAt(i - 1) == str2.charAt(j - 1))
                    dp[i][j] = dp[i - 1][j - 1] + 1;
                else
                    dp[i][j] = Math.max(dp[i - 1][j], dp[i][j - 1]);
            }
        }

        int index = dp[len1][len2];
        char[] lcs = new char[index];
        int i = len1, j = len2;
        while (i > 0 && j > 0) {
            if (str1.charAt(i - 1) == str2.charAt(j - 1)) {
                lcs[--index] = str1.charAt(i - 1);
                i--;
                j--;
            } else if (dp[i - 1][j] > dp[i][j - 1])
                i--;
            else
                j--;
        }

        System.out.println("Longest Common Subsequence: " + new String(lcs));
    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter first string: ");
        String str1 = sc.next();
        System.out.print("Enter second string: ");
        String str2 = sc.next();

        findLCS(str1, str2);
    }
}