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Math/Permutation.java

@@ -0,0 +1,47 @@
+import java.util.*;
+
+class Permutation{
+
+    static TreeSet<String> set = new TreeSet<>();
+
+    public static void permute(char[] arr, int start, int end){
+
+        if(start == end){
+            //System.out.println(String.valueOf(arr));
+            set.add(String.valueOf(arr));
+        }
+
+        else{
+            for(int i = start; i<=end; i++){
+                swap(arr, start, i);
+                permute(arr, start+1, end);
+                swap(arr, start, i);
+            }
+        }
+    }
+
+    static void swap(char[] arr, int i, int j){
+        char temp = arr[i];
+        arr[i] = arr[j];
+        arr[j] = temp;
+    }
+
+    public static void main(String[] args){
+        Scanner input = new Scanner(System.in);
+        System.out.println("Enter size of array: ");
+        int n = input.nextInt();
+        System.out.println("Enter the elements: ");
+        char[] arr = new char[n];
+        for(int i = 0; i<n; i++){
+            arr[i] = input.next().charAt(0);
+        }
+
+        permute(arr, 0, n-1);
+
+        for(String ele: set){
+            System.out.println(ele);
+        }
+
+        input.close();
+    }
+}