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| -rw-r--r-- | challenge-109/abigail/README.md | 1 | ||||
| -rw-r--r-- | challenge-109/abigail/awk/ch-2.awk | 126 |
2 files changed, 127 insertions, 0 deletions
diff --git a/challenge-109/abigail/README.md b/challenge-109/abigail/README.md index 1f7b55f195..3928e7302c 100644 --- a/challenge-109/abigail/README.md +++ b/challenge-109/abigail/README.md @@ -91,6 +91,7 @@ Output: ~~~~ ### Solutions +* [AWK](awk/ch-2.awk) * [Perl](perl/ch-2.pl) ### Blog diff --git a/challenge-109/abigail/awk/ch-2.awk b/challenge-109/abigail/awk/ch-2.awk new file mode 100644 index 0000000000..9476ec90e8 --- /dev/null +++ b/challenge-109/abigail/awk/ch-2.awk @@ -0,0 +1,126 @@ +#!/usr/bin/awk + +# +# See ../README.md +# + +# +# Run as: awk -f ch-2.awk < input-file +# + +{ + SIZE = 7; + # + # Put the fields into an array. + # + for (i = 1; i <= SIZE; i ++) { + numbers [i] = $i + } + + # + # Find all the differences between pairs of numbers + # + delete diffs + delete diff_count + for (i = 1; i <= SIZE; i ++) { + for (j = i + 1; j <= SIZE; j ++) { + diff = numbers [i] - numbers [j] + diff_count [ diff] ++ + diff_count [-diff] ++ + l1 = diff_count [ diff] + l2 = diff_count [-diff] + diffs [ diff, l1, 1] = i + diffs [ diff, l1, 2] = j + diffs [-diff, l2, 1] = j + diffs [-diff, l2, 2] = i + } + } + + # + # Iterate over the numbers, and see if there is a number + # which is equal to at least two differences. + # + # These numbers will be possibilities for d (at index d_i) + # + for (d_i = 1; d_i <= SIZE; d_i ++) { + d = numbers [d_i] + c = diff_count [d] + if (diff_count [d] >= 2) { + # + # Find two pairs whose difference is d, where none + # of the five numbers is reused. + # + for (i = 1; i <= c; i ++) { + if (diffs [d, i, 1] != d_i && diffs [d, i, 2] != d_i) { + for (j = i + 1; j <= c; j ++) { + if (diffs [d, j, 1] != d_i && + diffs [d, j, 2] != d_i && + diffs [d, i, 1] != diffs [d, j, 1] && + diffs [d, i, 1] != diffs [d, j, 2] && + diffs [d, i, 2] != diffs [d, j, 1] && + diffs [d, i, 2] != diffs [d, j, 2]) { + # + # W.l.o.g we can now assume diffs [d, i] + # contains the indices for a and c, + # and diffs [d, j] the indices for g and e. + # + a_i = diffs [d, i, 1] + c_i = diffs [d, i, 2] + g_i = diffs [d, j, 1] + e_i = diffs [d, j, 2] + + # + # Find the unused positions for b and f + # + for (b_i = 1; b_i <= SIZE; b_i ++) { + if (b_i != a_i && b_i != c_i && b_i != d_i && + b_i != e_i && b_i != g_i) { + for (f_i = 1; f_i <= SIZE; f_i ++) { + if (f_i != a_i && f_i != b_i && + f_i != c_i && f_i != d_i && + f_i != e_i && f_i != g_i) { + # + # Do we have a winner? + # + target = numbers [a_i] + \ + numbers [b_i] + if (target == numbers [b_i] + \ + numbers [c_i] + \ + numbers [d_i] && + target == numbers [d_i] + \ + numbers [e_i] + \ + numbers [f_i] && + target == numbers [f_i] + \ + numbers [g_i]) { + # + # We have a winner. Print + # it, and the reverse + # + printf "%d %d %d %d %d %d %d\n", + numbers [a_i], + numbers [b_i], + numbers [c_i], + numbers [d_i], + numbers [e_i], + numbers [f_i], + numbers [g_i] + printf "%d %d %d %d %d %d %d\n", + numbers [g_i], + numbers [f_i], + numbers [e_i], + numbers [d_i], + numbers [c_i], + numbers [b_i], + numbers [a_i] + } + } + } + } + } + } + } + } + } + } + } +} |