/* amoeba.tc - tct - 6/20/9, 7/8/9

amoeba [

 pl ""
 hilo '1';color '4';ps "amoeba.tc - tct - 7/8/9";pl ""

 pl "An amoeba either dies, lives, splits into two or splits into three,"
 pl "each with probability 1/4. It can be proved that, out of 100 simulations,"
 pl "about 100*(sqrt(2)-1), which equals about 41.4, populations will die out."
 pl "It can also be proved that 1.5^n is the expected number of amoebas"
 pl "after n generations. If n=30, 191751 amoebas are expected. If n=10,"
 pl "58 amoebas are expected."
 pl ""
 pl "Note: The Linux version of the tiny-c interpreter can handle 20+"
 pl "generations. The DOS version can do at most 13 generations."
 pl ""
 pl "Ref: http://yofx.blogspot.com/2009/06/amoeba-fever-problem.html"

 int c,p,pp,r,psp,g,s
 int sn,n,ptot /* n tracks generation, ptot tracks population count

 color '7';pl "";pl "seed? ";seed=last=gn
 ps "generations (e.g. 10 or 30)? ";sn=gn
 s=4 /* number of "runs" + 1
 while (--s) [ /* 1
  c=0;g=100;ptot=0 /* g is number of "simulations" in a "run"
  while (--g) [ /* 2
   p=psp=1
   n=sn+1
   while (--n*psp) [ /* 3
    for (pp=1;pp<=p;++pp) psp=psp+random(1,4)-2
    p=psp;if (!p) ++c
    ] /* 3
   ptot=ptot+p
   ] /* 2
  pl "";ps "Simulation #";pn 4-s;ps ".";pn c;ps " populations died out."
  pl "";pn ptot/100;ps " amoebas, on average, were living after"
  pn sn;ps " generations.";pl ""
  ] /* 1
 hilo '0'
 ]