此为北京大学的ACM练习网站上第1012题的源码，速度不算快，但AC了。-This is the practice site of Beijing University of ACM

杭电 hdu acm 第1084题的解法,ac过了,是一位学长教我的.内有一些中文说明.-Hangzhou Xinhua hdu acm section 1084 of title method, ac off, and is a senior teaching me. Note that there are Chinese.