#include pps/mathLib.tc
#include pps/library.tc

// prime.tc - 7/7/2014, 4/20/2019 - lrb

// 4/18,20/19 - added gcd support

prime int p,pa(0) [
 return(factor(p,pa)==p)
 ]

do [
 pa(0)=2;pa(1)=3;pa(2)=5;pa(3)=7;pa(4)=11;pa(5)=13
 pa(6)=17;pa(7)=19;pa(8)=23;pa(9)=29;pa(10)=31
 pa(11)=37;pa(12)=41;pa(13)=43;pa(14)=47;pa(15)=53
 pa(16)=59;pa(17)=61;pa(18)=67;pa(19)=71
 pa(20)=73;pa(21)=79;pa(22)=83;pa(23)=89
 pa(24)=97;pa(25)=101;pa(26)=103;pa(27)=107
 pa(28)=109;pa(29)=113;pa(30)=127;pa(31)=131
 pa(32)=137;pa(33)=139;pa(34)=149;pa(35)=151
 pa(36)=157;pa(37)=163;pa(38)=167;pa(39)=173
 pa(40)=179;pa(41)=181;pa(42)=191
 ]

test [
 do
 int pc
 ps "enter number : ";pc=gn;pn pc
 if pc>191*191 [pl "number too big";abort] // 4/20/2019
 if (prime(pc,pa)) ps " is prime."
 else ps " is composite."
 pl ""
 ]

int pa(42) // global

main int pc [
 do
 int w
 while ((w=factor(pc,pa))!=pc) [MC(w,14);ps "*";pc=pc/w]
 MC w,14
 pl ""
 ]

all [
 do
 int i,pc
 i=2
 int w
 while i<2000 [
  pc=i
  pn i;putchar ' '
  w=0
  while ((w=factor(pc,pa))!=pc) [MC(w,14);ps "*";pc=pc/w]
  MC w,14
  pl ""
  i=i+1
  ]
 ]

factor int f,pa(0) [ // returns smallest factor of f
 int j
 while j<=42 [
  if (f%pa(j)==0) return pa(j)
  j=j+1
  ]
 return f
 ]

mygcd [
 int first,second
 pl "enter first number : ";first=gn
 ps "enter second number : ";second=gn
 printf "The greatest common divisor of %d and %d is %d.%c",first,second,gcd(first,second),10
 ]