题解 | #[NOIP2015]金币#

#include <stdio.h>

int main() 
{
    int k = 0;
    scanf("%d",&k);
    int i = 1;
    int sum = 0;
    int day1 = 1;//计数
    int day2 = 1;//天数上限，同时是需要加的金币值
    for(i = 1; i <=k; i++)
    {
        sum += day2;
        if(day1 == day2)
        {
            day1 = 1;
            day2++;
        }
        else 
        {
            day1++;
        }
    }
    printf("%d\n",sum);
    return 0;
}