Question

java 请用 递归 实现 1 至 100 的和

Answer 1

public class Test {

public static void main(String[] args) {
System.out.println(dg(100));
}

static int dg(int i) {
int sum;
if (i == 1)
return 1;
else
sum = i + dg(i - 1);
return sum;
}
}

Answer 2

public class MyDay{
public static void main(String[] args){
MyDay m=new MyDay();
int sum=m.fun(100);
System.out.println("1+2+......100="+sum);
}
public int fun(int n){

if(n==1)
return 1;
else
return n+fun(n-1);
}
}

Answer 3

public static void main(String args[]){
int sum=0;
for(int i=1;i<=100;i++){
sum+=i;
}
System.out.println(sum);
}

Answer 4

public Sum (int n){
if(int n=100;n<1;n--);
n=n+1;
return n;
}