RosettaCodeData/Task/Superpermutation-minimisation/AWK/superpermutation-minimisati...

49 lines
962 B
Awk

# syntax: GAWK -f SUPERPERMUTATION_MINIMISATION.AWK
# converted from C
BEGIN {
arr[0] # prevents fatal: attempt to use scalar 'arr' as an array
limit = 11
for (n=0; n<=limit; n++) {
leng = super_perm(n)
printf("%2d %d ",n,leng)
# for (i=0; i<length(arr); i++) { printf(arr[i]) } # un-comment to see the string
printf("\n")
}
exit(0)
}
function fact_sum(n, f,s,x) {
f = 1
s = x = 0
for (;x<n;) {
f *= ++x
s += f
}
return(s)
}
function super_perm(n, i,leng) {
delete arr
pos = n
leng = fact_sum(n)
for (i=0; i<leng; i++) {
arr[i] = ""
}
for (i=0; i<=n; i++) {
cnt[i] = i
}
for (i=1; i<=n; i++) {
arr[i-1] = i + "0"
}
while (r(n)) { }
return(leng)
}
function r(n, c) {
if (!n) { return(0) }
c = arr[pos-n]
if (!--cnt[n]) {
cnt[n] = n
if (!r(n-1)) { return(0) }
}
arr[pos++] = c
return(1)
}