String Compression in Java

1import java.util.Scanner;
2
3public class Main {
4    public static String compress(String s) {
5        if (s.isEmpty()) return s;
6        StringBuilder sb = new StringBuilder();
7        char prev = s.charAt(0);
8        int count = 1;
9        for (int i = 1; i < s.length(); i++) {
10            char c = s.charAt(i);
11            if (c == prev) {
12                count++;
13            } else {
14                sb.append(prev).append(count);
15                prev = c;
16                count = 1;
17            }
18        }
19        sb.append(prev).append(count);
20        return sb.toString();
21    }
22
23    public static void main(String[] args) {
24        Scanner sc = new Scanner(System.in);
25        System.out.print("Enter a string: ");
26        String s = sc.nextLine();
27
28        System.out.println("Compressed: " + compress(s));
29        sc.close();
30    }
31}