package me.ramswaroop.strings;
/**
* Created by IntelliJ IDEA.
*
* @author: ramswaroop
* @date: 9/26/15
* @time: 4:43 PM
*/
public class UppercaseLowercasePermutations {
/**
* Generates all possible case combinations for string {@param s}.
* <p/>
* For example,
* Input: 0ab
* Output: ["0ab","0AB","0aB","0Ab"]
*
* @param prefix
* @param s
*/
public static void printUppercaseLowercasePermutations(String prefix, String s) {
if (s.isEmpty()) {
System.out.println(prefix);
return;
}
if (!isNumber(s.charAt(0))) {
printUppercaseLowercasePermutations(prefix + Character.toUpperCase(s.charAt(0)), s.substring(1));
printUppercaseLowercasePermutations(prefix + Character.toLowerCase(s.charAt(0)), s.substring(1));
} else {
printUppercaseLowercasePermutations(prefix + s.charAt(0), s.substring(1));
}
}
public static boolean isNumber(char s) {
try {
Integer.parseInt(String.valueOf(s));
} catch (Exception e) {
return false;
}
return true;
}
public static void main(String a[]) {
printUppercaseLowercasePermutations("", "0ab");
System.out.println("========");
printUppercaseLowercasePermutations("", "01");
System.out.println("========");
printUppercaseLowercasePermutations("", "0a1");
System.out.println("========");
printUppercaseLowercasePermutations("", "0ab1c");
}
}