import java.util.*; public class Main { public static void main(String[] args) { Scanner sc = new Scanner(System.in); double n = sc.nextDouble(); int x = (int)(Math.sqrt(2*n)); if((x+1)*x / 2 < n) { System.out.println(x+1); } else { System.out.println(x); } } }例如,n=7,8,9,10时,x范围是(3或者4)(4或者5),用if语...