CQU_HYX的专栏

 I - Finding Black Circles Time Limit:10000MS     Memory Limit:0KB     64bit IO Format:%lld & %llu 这道题，刘汝佳书上说了解法很多，我百度之，并没有找到任何题解，然后便一直坑之，最后终于坑出来了。 大致的思路就是，枚举圆心p，然后扫长度len（4个方向），如果该半径延伸到的距离

The shuffle Problem Description Any case of shuffling of n cards can be described with a permutation of 1 to n. Thus there are totally n! cases of shuffling. Now suppose there are 5 cards, and a case