递归（斐波那契，阶乘）

public class Drawinferences {

public static void main(String[] args) {
System.out.println(Fbnc(-8));
System.out.println(Jc(5));
System.out.println(SumJc(4));

        
}
//阶乘的和

private static int SumJc(int i) {
if(i==1){
return 1;
}else{
return SumJc(i-1)+Jc(i);
}

}

//阶乘
private static int Jc(int i) {
if(i==1){
return 1;
}
else{
return Jc(i-1)*i;
}
}

//斐波那契
public static int Fbnc(int n) {
if (n < 0) {
return 0;
} else if (n == 1 || n == 2) {
return 1;
} else {
return Fbnc(n - 1) + Fbnc(n - 2);
}
}

}