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#!/usr/bin/awk
#
# See ../README.md
#
#
# Run as: awk -f ch-2.awk < input-file
#
function digit_sum (number, sum) {
sum = 0
while (number > 0) {
sum += number % 10
number = int (number / 10)
}
return sum
}
#
# Factorize a number, given a set of small primes. This will work
# for numbers up to, but not including, p^2, where p is the smallest
# prime not included in the set. For the given set, the smallest number
# which fails to factorize is 37^2 == 1369.
#
# We'll return a string containing all the factors.
#
function factorize (n, out, i, prime, c) {
out = ""
c = 0
for (i in small_primes) {
prime = small_primes [i]
while (n % prime == 0) {
out = out prime
n /= prime
c ++
}
}
if (n > 1) {
out = out n
c ++
}
return (c ";" out)
}
BEGIN {
split ("2 3 5 7 11 13 17 19 23 29 31", small_primes, " ")
}
BEGIN {
try = 1
count = 0
while (count < 10) {
split (factorize(try), info, ";")
if (info [1] > 1 && digit_sum(try) == digit_sum(info [2])) {
print try
count ++
}
try ++
}
}
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