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  • hzau 1204 Escape from the Darkness

    1204: Escape from the Darkness

    Time Limit: 1 Sec  Memory Limit: 1280 MB
    Submit: 93  Solved: 3
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    Description

         Xiao Ming, a high school student, learnt blackbody radiation from the physics class. The black body on the book is indicated approximately by black body cavity as below: 

     from the small hole if total reflection occurs on the surface of the cavity.

        Assuming in the two-dimensional coordinates, the center of the oval is at origin, and the vertexes of it is respectively (a, 0), (-a, 0), (0, b), (0, -b). There is a small hole at (a/2,sqrt(3)*b/2) (whose areas can be ignored). A beam of light (whose diameter can be ignored) shoot into the oval through the small hole. The direction of the light is (-1, 0). Assuming the light totally mirror reflects on the surface of the oval, the question is how many times can the light reflect before shooting out through the small hole. (If a point is away from the small hole less than 0.01, we think light shoot out from that point.)

    Input

         The first line is a positive integer T (1 <= T <= 55) which indicates the numbers of the test cases. Then flowing next T lines, there are two positive integer a, b (1 <= b<= a<= 10) in each line as a group of cases. 

    Output

         The output of each case is one line with a positive integer which indicates the times of reflects. 

    Sample Input

    1
    1 1
    

    Sample Output

    5
    

    HINT

     The path of the light in the sample is looked as the picture shows. The light reflected five times.


    Source

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  • 原文地址:https://www.cnblogs.com/gongpixin/p/6790501.html
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