String-2 > repeatFront

Given a string and an int n, return a string made of the first n characters of the string, followed by the first n-1 characters of the string, and so on. You may assume that n is between 0 and the length of the string, inclusive (i.e. n >= 0 and n <= str.length()).

repeatFront("Chocolate", 4) → "ChocChoChC"
repeatFront("Chocolate", 3) → "ChoChC"
repeatFront("Ice Cream", 2) → "IcI"

Definiujemy zmienna newStr , loop reverse schodzimy od n do 0 i kazdy substring dodajemy do nwoego newStr

public String repeatFront(String str, int n) {
  String newStr = "";
  for (int i=n; i>=0; i--){
    newStr+=str.substring(0,i);
  }return newStr;
}