w3school遞迴方法.recursion遞迴再出現

//方思涵練習檔//
public class Main {
  public static void main(String[] args) {
    int x=10;
    for (int i=0; i 0) { return k + sum(k - 1); } 
    else { return 0;}
  }
public static int f(int k) {
    if (k > 0) {
      return k * f(k - 1);
    } else {return 1; }
}
}