运行效果:
代码:
public class Demo1 {
public static void main(String[] args) {
System.out.print("请输入一个数:");
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
Sum(n);
System.out.println(Sum(n));
}
private static int Sum(int n) {
if (n == 0) {
return 0;
}
return Sum(n - 1) + n;
}
}
思路:
计算前n个数的总和等于第n-1个数+n;