Print all Subsequences of a String

Problem Statement

Pattern:

---

Solution

static void dp(char[] s, int n, StringBuilder sb) {
	if(n <= 0) {
		System.out.println(sb.reverse());
		sb.reverse();
		return;
	}
	
	dp(s, n-1, sb.append(s[n-1]));
	if(sb.length() > 0) sb.delete(sb.length()-1, sb.length());
	dp(s, n-1, sb);
}
 
// region MAIN
public static void main(String[] args) {
	dp("Something".toCharArray(), "Something".length(), new StringBuilder());
}

TC : $2^n$ SC : $2^n$

Notes

• can be optimised with memoisation