菜鸡的博客

Mr. West bought a new car! So he is travelling around the city. One day he comes to a vertical corner. The street he is currently in has a width x, the street he wants to turn to has a width y. The ca...

当答案具有可二分性时，我们可以用二分答案来解决。但是，如果要求出凸性函数或凹性函数的最值时，二分就毫无用武之地了，这时，我们就可以用三分法来求出答案。 一个凸性序列/凹性序列通俗的说法就是在该序列最大值/最小值的左边满足不严格单调递增/递减，右边满足不严格单调递减/递增。如1,2,3,6,4是一个凸性序列，而5,4,4,3,1,2,4,6是一个凹性序列（见下图），而图中的6和1就分别是两个序列...