RosettaCodeData/Task/Greatest-subsequential-sum/AWK/greatest-subsequential-sum-...

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636 B
Awk

# Finds the subsequence of ary[1] to ary[len] with the greatest sum.
# Sets subseq[1] to subseq[n] and returns n. Also sets subseq["sum"].
# An empty subsequence has sum 0.
function maxsubseq(subseq, ary, len, b, bp, bs, c, cp, i) {
b = 0 # best sum
c = 0 # current sum
bp = 0 # position of best subsequence
bn = 0 # length of best subsequence
cp = 1 # position of current subsequence
for (i = 1; i <= len; i++) {
c += ary[i]
if (c < 0) {
c = 0
cp = i + 1
}
if (c > b) {
b = c
bp = cp
bn = i + 1 - cp
}
}
for (i = 1; i <= bn; i++)
subseq[i] = ary[bp + i - 1]
subseq["sum"] = b
return bn
}