蓝桥杯--金币

https://www.lanqiao.cn/problems/357/learning/?contest_id=55

#include <stdio.h>
#include <stdlib.h>

int main()
{
  int i=1;
  int sum=1,k,ans=0;
  scanf("%d",&k);
  while(sum<k){
    if(sum+i>k)break;
    ans=ans+i*i;
    sum=sum+i;
    i++;
  }
  ans=ans+i*(k-sum+1);
  printf("%d",ans);
  return 0;
}