import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int n = sc.nextInt(); int count = 0; for(int i = 0; i <= n; i++){ int sum = 0; for(int j = 0; j <= n / 2; j++){ for(int k = 0; k <= n / 5; k++){ sum = i * 1 + j * 2 + k * 5; if(sum == n){ count++; break; } } } } System.out.println(count); } }这题我用三层循环写的,将1放在最外面的循环,将2放在中间,将5放在里面,然后凑数,符合这个数就count++,最后输出count。