Primality by Wilson's theorem: Difference between revisions

=={{header|AWK}}==

<lang AWK>

# syntax: GAWK -f PRIMALITY_BY_WILSONS_THEOREM.AWK

# converted from FreeBASIC

BEGIN {

start = 2

stop = 200

for (i=start; i<=stop; i++) {

if (is_wilson_prime(i)) {

printf("%5d%1s",i,++count%10?"":"\n")

}

}

printf("\nWilson primality test range %d-%d: %d\n",start,stop,count)

exit(0)

}

function is_wilson_prime(n, fct,i) {

fct = 1

for (i=2; i<=n-1; i++) {

# because (a mod n)*b = (ab mod n)

# it is not necessary to calculate the entire factorial

fct = (fct * i) % n

}

return(fct == n-1)

}

</lang>

{{out}}

<pre>

2 3 5 7 11 13 17 19 23 29

31 37 41 43 47 53 59 61 67 71

73 79 83 89 97 101 103 107 109 113

127 131 137 139 149 151 157 163 167 173

179 181 191 193 197 199

Wilson primality test range 2-200: 46

</pre>