题解 | #数字序列第n位的值#

import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; public class Main{ public static void main(String[] args)throws IOException{ BufferedReader in = new BufferedReader(new InputStreamReader(System.in)); int n = Integer.parseInt(in.readLine()); int i = (int)Math.sqrt(2*n); while(((i+1)*i)/2 <n){ i ++; } System.out.println(i); } }