POJ 3440 Coin Toss(概率)

题目链接

概率问题，像是概率论上学的均匀分布，是不是呢，忘了。。。

概率同面积有关系，我写的各种搓，然后此题格式十分变态，=前有的时候俩空格，有的时候一个空格。代码各种搓。

 1 #include <cstdio>

 2 #include <cstring>

 3 #include <iostream>

 4 #include <cmath>

 5 #include <algorithm>

 6 using namespace std;

 7 #define PI 3.141592653

 8 #define eps 1e-9

 9 int main()

10 {

11     int t,cas = 1;

12     double n,m,d,r,S;

13     double t11,t12,t13,t14,t21,t22,t23,t24,t31,t32,t33,t34;

14     double a1,a2,a3,a4;

15     scanf("%d",&t);

16     while(t--)

17     {

18         scanf("%lf%lf%lf%lf",&n,&m,&d,&r);

19         S = n*m*d*d;

20         t11 = (d-r/2)*(d-r/2);

21         t12 = 2*(d-r/2)*r/2;

22         t13 = 0.25*PI*(r/2)*(r/2);

23         t14 = (r/2)*(r/2) - t13;

24         t21 = (d-r/2)*(d-r);

25         t22 = (d-r/2)*r + (d-r)*r/2;

26         t23 = 0.5*PI*(r/2)*(r/2);

27         t24 = 2*(r/2)*(r/2) - t23;

28         t31 = (d-r)*(d-r);

29         t32 = 4*(d-r)*r/2;

30         t33 = PI*(r/2)*(r/2);

31         t34 = r*r - t33;

32         if(n == 1&&m == 1)

33         {

34             a1 = S;

35             a2 = 0;

36             a3 = 0;

37             a4 = 0;

38         }

39         else if(n == 1)

40         {

41             a1 = 2*(d-r/2)*d + (m-2)*(d-r)*d;

42             a2 = S - a1;

43             a3 = 0;

44             a4 = 0;

45         }

46         else if(m == 1)

47         {

48             a1 = 2*(d-r/2)*d + (n-2)*(d-r)*d;

49             a2 = S - a1;

50             a3 = 0;

51             a4 = 0;

52         }

53         else

54         {

55             a1 = 4*t11 + 2*(n-2+m-2)*t21 + (n-2)*(m-2)*t31;

56             a2 = 4*t12 + 2*(n-2+m-2)*t22 + (n-2)*(m-2)*t32;

57             a3 = 4*t13 + 2*(n-2+m-2)*t23 + (n-2)*(m-2)*t33;

58             a4 = 4*t14 + 2*(n-2+m-2)*t24 + (n-2)*(m-2)*t34;

59         }

60         printf("Case %d:\n",cas++);

61         printf("Probability of covering 1 tile  = %.4f%%\n",a1*100/S);

62         printf("Probability of covering 2 tiles = %.4f%%\n",a2*100/S);

63         printf("Probability of covering 3 tiles = %.4f%%\n",a4*100/S);

64         printf("Probability of covering 4 tiles = %.4f%%\n",a3*100/S);

65         printf("\n");

66     }

67     return 0;

68 }