Update Permutation.java

Author: siddarthjha

Basics Java/src/Practice/Problems/Permutation.java

@@ -1 +1,44 @@
+import java.util.Scanner;
+import static java.lang.System.*;
+
+public class Permutation
+{
+	public static void main(String[] args)
+	{
+		Scanner sc = new Scanner(System.in);
+		String s = sc.nextLine();
+		int len = s.length();
+		out.println("The string is " + s);
+		permutation(s, 0, len);
+	}
+	
+	public static void permutation(String str, int start, int end)  
+    {  
+        //Prints the permutations  
+        if (start == end-1)  
+            System.out.println(str);  
+        else  
+        {  
+            for (int i = start; i < end; i++)  
+            {  
+                //Swapping the string by fixing a character  
+                str = swapString(str,start,i);  
+                //Recursively calling function generatePermutation() for rest of the characters   
+                permutation(str,start+1,end);  
+                //Backtracking and swapping the characters again.  
+                str = swapString(str,start,i);  
+            }  
+        } 
+	}
+	
+	public static String swapString(String a, int i, int j) 
+	{  
+        char[] b =a.toCharArray();  
+        char ch;  
+        ch = b[i];  
+        b[i] = b[j];  
+        b[j] = ch;  
+        return String.valueOf(b);  
+    }  
+}