Permutations.java

public class Permutations {

 public static void main(String[] args) {
 permutations("", "abc");
 }
 
 static void permutations(String p, String up) {
 // Base case: If the remaining characters to be permuted is empty, print the permutation
 if (up.isEmpty()) {
 System.out.println(p);
 return;
 }
 
 char ch = up.charAt(0);
 
 for (int i = 0; i <= p.length(); i++) {
 // Split the permutation string into two parts
 String f = p.substring(0, i); // First part
 String s = p.substring(i, p.length()); // Second part
 
 // Recursive call: Generate permutations by inserting the current character at each possible position
 permutations(f + ch + s, up.substring(1));
 }
 }
 }