题目226：一勺牛奶冻

欧拉计划

A Scoop of Blancmange

The blancmange curve is the set of points (x,y) such that 0 ≤ x ≤ 1 and
  ,
where s(x) = the distance from x to the nearest integer.

The area under the blancmange curve is equal to ½, shown in pink in the diagram below.

Let C be the circle with centre (¼,½) and radius ¼, shown in black in the diagram.

What area under the blancmange curve is enclosed by C?
Give your answer rounded to eight decimal places in the form 0.abcdefgh

题目：

牛奶冻曲线是点 (x,y) 的集合,其中 0 ≤ x ≤ 1，
，
上式中的 s(x) = x 与最近整数之间的距离。

牛奶冻曲线下的面积为 ½，如下面的粉红角区域所示。

令 C 为以（¼,½）为圆心，半径为 ¼ 的圆，如图中的黑色区域所示。

求 C 与牛奶冻曲线相交部分的面积。

答案保留８位小数，形式为：0.abcdefgh