题解 | #[NOIP2015]金币#

import java.util.Scanner; public class Main { public static void main(String[] args) {

•   Scanner sc = new Scanner(System.in);
    int k = sc.nextInt();
    int day = 0;
    int sum = 0;
    for(int i=1;i<=10000;i++) {
    	for(int j=1;j<=i;j++) {
    		sum += i;
    		day++;
    		if(day == k) {
    			System.out.println(sum);
    			break;
    		}
    	}
    }
  

  }

}