题解 | #[NOIP2015]金币#

#include <stdio.h>

int main()
{
	int day = 0, n, i, j, sum = 0, count = 1;
	scanf("%d", &n);
while(day<n)
	{
		for (j = 1; j <= count; j++)
		{
			sum += count;
			day++;
			if (day==n)
			{
				break;
			}
		}
		count++;
	}
	printf("%d\n", sum);
	return 0;
}