 狗狗昂赛-新鲜面筋2019-11月份

1. true or false

1.R only can go right

2.L only can go left

3.R and L can't cross

ie.

Input: R _ _ _ L _ _ R _

output: R L _ _ _ _ _ _ R

return True

[explanation: input L went to left, andinput R went to right become output.]

ie.

Input:  R _ _ _ L _ _ R _

output: L R _ _ _ _ _ _ R

return False

(follow up： what ifone cross is allowed, how to solve it)

2.

Find the rate that Teacher didn't catchstudent cheat:

S stands for a student.

The teacher sits in front of the first row:

-------------------------------------------------

Teacher

S1  S2   S3   S4  S5

S6  S7   S8   S9 S10

S11 S12 S13 S14 S15

S16 S17 S18 S19 S20

....

the first-row student  got caught rate is 0.9

the second-row student  got caught rate is 0.9 / 2

the third-row student got caught rate is0.9 / 4

.....

the first column student  got caught rate is 0.5

the second column student  got caught rate is 0.5/ 2

the third column student  got caught rate is 0.5 / 4

the fourth column student  got caught rate is 0.5 / 8

....

Give you a path, find the possibility(rate)that path of students will NOT be caught.

ie.:

1. S1 to S2 caught rate is 0.9.

2. S1 to S3 caught rate is 0.9 * 0.9

3. S4 to S9 caught rate is 0.5

...

what if the path：S1 ->S6 -> S7 -> S12 -> S17？

Write a function to find the student notbeing caught rate for this path.

*/