题解 | #牛牛学数列# 递归解法
牛牛学数列
http://www.nowcoder.com/practice/0b97367cd2184c12a0e02f7c223aee11
import java.util.Scanner;
public class Main{
public static void main(String[] args){
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
System.out.println(sum(n));
}
return 1;
}
if(n % 2 == 0){
return sum(n-1) - n;
}else{
return sum(n-1) + n;
}
}
}
public class Main{
public static void main(String[] args){
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
System.out.println(sum(n));
}
public static int sum(int n){
// 注意递归的返回条件，避免死循环
if(n == 1){return 1;
}
if(n % 2 == 0){
return sum(n-1) - n;
}else{
return sum(n-1) + n;
}
}
}
查看20道真题和解析
