feat : new recursion algos TowerOfHanoi.java and GenerateUniqueSubsets.java added

src/main/java/com/thealgorithms/Recursion/GenerateSubsets.java

@@ -5,6 +5,11 @@
 import java.util.ArrayList;
 import java.util.List;
 
+/**
+ * Finds all permutations of given array
+ * @author Tuhin Mondal (<a href="https://github.com/tuhinm2002">Git-Tuhin Mondal</a>)
+ */
+
 public final class GenerateSubsets {
 
     private GenerateSubsets() {

src/main/java/com/thealgorithms/Recursion/GenerateUniqueSubsets.java

@@ -0,0 +1,47 @@
+package com.thealgorithms.Recursion;
+
+// program to find unique power set of a string
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+/**
+ * Finds all permutations of given array
+ * @author Tuhin Mondal (<a href="https://github.com/tuhinm2002">Git-Tuhin Mondal</a>)
+ */
+
+public final class GenerateUniqueSubsets {
+
+    private GenerateUniqueSubsets() {
+        throw new UnsupportedOperationException("Utility class");
+    }
+
+    public static List<String> subsetRecursion(String str) {
+        Set<String> ans = doRecursion("", str);
+        List<String> a = new ArrayList<>(ans.stream().toList());
+        Collections.sort(a);
+        return a;
+    }
+
+    private static Set<String> doRecursion(String p, String up) {
+        if (up.isEmpty()) {
+            Set<String> list = new HashSet<>();
+            list.add(p);
+            return list;
+        }
+
+        // Taking the character
+        char ch = up.charAt(0);
+        // Adding the character in the recursion
+        Set<String> left = doRecursion(p + ch, up.substring(1));
+        // Not adding the character in the recursion
+        Set<String> right = doRecursion(p, up.substring(1));
+
+        left.addAll(right);
+
+        return left;
+    }
+}

src/main/java/com/thealgorithms/Recursion/TowerOfHanoi.java

@@ -0,0 +1,32 @@
+package com.thealgorithms.Recursion;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Finds all permutations of given array
+ * @author Tuhin Mondal (<a href="https://github.com/tuhinm2002">Git-Tuhin Mondal</a>)
+ */
+
+public final class TowerOfHanoi {
+    private TowerOfHanoi() {
+        throw new UnsupportedOperationException("Utility class");
+    }
+
+    public static List<String> towerOfHanoi(int n) {
+        List<String> arr = new ArrayList<>();
+        recursionApproach(n, 'A', 'B', 'C', arr);
+        return arr;
+    }
+
+    public static void recursionApproach(int n, char a, char b, char c, List<String> list) {
+        if (n == 1) {
+            list.add("Take disk 1 from rod " + a + " to rod " + b);
+            return;
+        }
+
+        recursionApproach(n - 1, a, c, b, list);
+        list.add("Take disk " + n + " from rod " + a + " to rod " + b);
+        recursionApproach(n - 1, c, b, a, list);
+    }
+}