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Write a Java Program to Compute all the permutations of the string
PROGRAM: Java Program to Compute all the permutations of the string
/*Java Program to Compute all the permutations of the string*/
import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;
class Main {
public static Set<String> getPermutation(String str) {
// create a set to avoid duplicate permutation
Set<String> permutations = new HashSet<String>();
// check if string is null
if (str == null) {
return null;
} else if (str.length() == 0) {
// terminating condition for recursion
permutations.add(“”);
return permutations;
}
// get the first character
char first = str.charAt(0);
// get the remaining substring
String sub = str.substring(1);
// make recursive call to getPermutation()
Set<String> words = getPermutation(sub);
// access each element from words
for (String strNew : words) {
for (int i = 0;i<=strNew.length();i++){
// insert the permutation to the set
permutations.add(strNew.substring(0, i) + first + strNew.substring(i));
}
}
return permutations;
}
public static void main(String[] args) {
// create an object of scanner class
Scanner input = new Scanner(System.in);
// take input from users
System.out.print(“Enter the string: “);
String data = input.nextLine();
System.out.println(“Permutations of ” + data + “: \n” + getPermutation(data));
}
}
