1.  It is late
night and a drunkard is walking along a very long street.  The
drunkard is not sure which is the way home, so he randomly takes steps
of length 1.0 m forward or backward. He takes one step every second
continuously for 1 hr. 
a. Simulate this process by using a
random number generator . Note that  the C Library provides
one;  use man srand to
learn more about this. 
b. Generate 100 different realizations of  the  random
sequence of steps by using a different seed each  time.  
c. Graphically show the randomwalks.
d. Calculate the displacement of the drunkard for each realization, and
show graphically how these are distributed using a histogram. 
e. Calculate the mean and the  root mean square (rms.)
displacement of  the drunkard after 1hr. 
f. Increase the time (number of steps) and show that the mean
displacement  tends to 0 and the rms. displacement scales as the
square -root of the time.  Also try to derive the same result
analyticaly.