检查字符串是否与另一个字符串构成的字母相同

Question

The topic explains my wish pretty well i think. So what i want to reach is:

madeOutOfSameLetters("aaasdf", "xyz") // false
madeOutOfSameLetters("aaasdf", "asdf") // false
madeOutOfSameLetters("aaasdf", "aaasdd") // false
madeOutOfSameLetters("aaasdf", "fdsaaa") // true

Is there a (combination of) method(s) I can use for, or do I need to do it by my own?

In second case I would count each letter of both strings, write it into arrays and compare them to each other. But that seems to be more complicated than it has to be to me. Any easier ideas?

Answer 1

You could use String.toCharArray() and Arrays.sort(char[]) and Arrays.equals(char[], char[]) . That is, something like,

public static boolean madeOutOfSameLetters(String a, String b) {
    if (a == null) {
        return b == null;
    } else if (b == null) {
        return false;
    }
    char[] left = a.toCharArray();
    char[] right = b.toCharArray();
    Arrays.sort(left);
    Arrays.sort(right);
    return Arrays.equals(left, right);
}

public static void main(String[] args) throws Exception {
    System.out.println(madeOutOfSameLetters("aaasdf", "xyz")); // false
    System.out.println(madeOutOfSameLetters("aaasdf", "asdf")); // false
    System.out.println(madeOutOfSameLetters("aaasdf", "aaasdd")); // false
    System.out.println(madeOutOfSameLetters("aaasdf", "fdsaaa"));// true
}

Output is the requested

false
false
false
true

Answer 2

An easier idea:

1. Sort the letters on each string s1 and s2 .
2. Remove duplicate letters from s1 and s2 .
3. Check if s1 is equal to s2 . If it is, then both strings are "made out of same letters". Otherwise, they don't.

Hope it helps.