diff options
| -rw-r--r-- | iterative-add/iterative-add-test.scm | 20 | ||||
| -rw-r--r-- | iterative-add/iterative-add.scm | 15 | ||||
| -rw-r--r-- | report-repair/README.org | 71 | ||||
| -rw-r--r-- | report-repair/input.txt | 200 | ||||
| -rwxr-xr-x | report-repair/main.scm | 19 | ||||
| -rw-r--r-- | report-repair/rr-test.scm | 83 | ||||
| -rw-r--r-- | report-repair/rr.scm | 65 |
7 files changed, 473 insertions, 0 deletions
diff --git a/iterative-add/iterative-add-test.scm b/iterative-add/iterative-add-test.scm new file mode 100644 index 0000000..d318570 --- /dev/null +++ b/iterative-add/iterative-add-test.scm @@ -0,0 +1,20 @@ +;; -*- compile-command: "guile -L . iterative-add-test.scm"; -*- +(use-modules (srfi srfi-64) + (iterative-add)) + + +(test-begin "harness") + +(test-equal "add 0 to 1" + 1 + (iterative-add-generator 1)) + +(test-equal "add 1 to 2" + 3 + (iterative-add-generator 2)) + +(test-equal "add 2 to 6" + 8 + (iterative-add-generator 6)) + +(test-end "harness") diff --git a/iterative-add/iterative-add.scm b/iterative-add/iterative-add.scm new file mode 100644 index 0000000..45c6cf9 --- /dev/null +++ b/iterative-add/iterative-add.scm @@ -0,0 +1,15 @@ +(define-module (iterative-add) + #:export (iterative-add-generator)) + +(define iterative-add + (let ((prev-num 0)) + (lambda (num) + (let ((result + (+ num prev-num))) + (set! prev-num num) + result)))) + +(define (iterative-add-generator num) + "Adds the previously received +number to the current one." + (iterative-add num)) diff --git a/report-repair/README.org b/report-repair/README.org new file mode 100644 index 0000000..32faec1 --- /dev/null +++ b/report-repair/README.org @@ -0,0 +1,71 @@ +See: https://adventofcode.com/2020/day/1 +** Part 1 +*** Purpose +Given a list of numbers (report): + +#+begin_example +1721 +979 +366 +299 +675 +1456 +#+end_example + +This program takes two entries that sum to 2020 (in the above example, it is 1721 and 299) and multiplies them together. + +*** Method + +To do this, the program takes the full list of numbers and subtracts them from 2020: + +#+begin_example +299 +1041 +1654 +1721 +1345 +564 +#+end_example + +It stores this as a list of cons pairs: + +#+begin_example +'((299 . 1721) + (1041 . 979) + (1654 . 366) + (1721 . 299) + (1345 . 675) + (564 . 1456)) +#+end_example + +Now, we find a pair that is equivalent on the basis of containing the same elements, and complete the multiplication. + +** Part 2 +*** Purpose +Of course, we now need to find three numbers in the list that meet the same criteria... + +Say we have a list: + +#+begin_example +979 +366 +675 +#+end_example + +We calculate a list of key-value pairs---each number added to every other number... + +#+begin_example +'((((979 366) . 1345) + ((979 675) . 1654) + ((366 675) . 1041)) +#+end_example + +Then, we perform the same operation as we did in the first part: + +#+begin_example +'((((979 366 675) . 1345) + ((979 675 366) . 1654) + ((366 675 979) . 1041))) +#+end_example + +And we simply check if all three values in the car position are in the original set of numbers. diff --git a/report-repair/input.txt b/report-repair/input.txt new file mode 100644 index 0000000..fc2d3b1 --- /dev/null +++ b/report-repair/input.txt @@ -0,0 +1,200 @@ +1941 +1887 +1851 +1874 +1612 +1960 +1971 +1983 +1406 +1966 +1554 +1892 +1898 +1926 +1081 +1992 +1073 +1603 +177 +1747 +1063 +1969 +1659 +1303 +1759 +1853 +1107 +1818 +1672 +1352 +2002 +1838 +1985 +1860 +1141 +1903 +1334 +1489 +1178 +1823 +1499 +1951 +1225 +1503 +1417 +1724 +1165 +1339 +1816 +1504 +1588 +1997 +1946 +1324 +1771 +1982 +1272 +1367 +1439 +1252 +1902 +1940 +1333 +1750 +1512 +1538 +1168 +2001 +1797 +1233 +972 +1306 +1835 +1825 +1822 +1880 +1732 +1785 +1727 +1275 +1355 +1793 +1485 +1297 +1932 +1519 +1587 +1382 +1914 +1745 +1087 +1996 +1746 +1962 +1573 +2008 +1868 +1278 +1386 +1238 +1242 +1170 +1476 +1161 +1754 +1807 +1514 +1189 +1916 +1884 +1535 +1217 +1911 +1861 +1493 +1409 +1783 +1222 +1955 +1673 +1502 +607 +2010 +1846 +1819 +1500 +1799 +1475 +1146 +1608 +1806 +1660 +1618 +1904 +978 +1762 +1925 +1185 +1154 +1239 +1843 +1986 +533 +1509 +1913 +287 +1707 +1115 +1699 +1859 +1077 +1915 +1412 +1360 +1646 +1973 +1627 +1755 +1748 +1769 +1886 +1422 +1686 +950 +100 +1372 +1068 +1370 +1428 +1870 +1108 +190 +1891 +1794 +1228 +1128 +1365 +1740 +1888 +1460 +1758 +1906 +1917 +1989 +1251 +1866 +1560 +1921 +1777 +1102 +1850 +1498 +683 +1840 +1800 +1112 +1908 +1442 +1082 +1071 diff --git a/report-repair/main.scm b/report-repair/main.scm new file mode 100755 index 0000000..cdfed63 --- /dev/null +++ b/report-repair/main.scm @@ -0,0 +1,19 @@ +#!/run/current-system/profile/bin/guile \ +-e main -s +!# + +(use-modules (rr) + ((ice-9 rdelim)) + (ice-9 binary-ports)) + + +(define (stdin-to-str) + (let loop ((result "")) + (let ((line (read-line))) + (if (eof-object? line) + result + (loop (string-append result line " ")))))) + +(define (main args) + (display (rr (stdin-to-str))) + (newline)) diff --git a/report-repair/rr-test.scm b/report-repair/rr-test.scm new file mode 100644 index 0000000..7d75c09 --- /dev/null +++ b/report-repair/rr-test.scm @@ -0,0 +1,83 @@ +;; -*- compile-command: "guile -L . rr-test.scm"; -*- +(use-modules (srfi srfi-64) + (rr)) + +(test-begin "harness") + + +(test-equal "friendship 1" + '(1 . 2019) + (return-friendship-pair 1)) + +(test-equal "friendship 1596" + '(1596 . 424) + (return-friendship-pair 1596)) + +(test-equal "small report" + '((0 . 2020) + (1 . 2019) + (2 . 2018) + (3 . 2017) + (4 . 2016) + (5 . 2015)) + (report->pairs "0 1 2 3 4 5")) + +(test-assert "equivalent pair" + (equivalent-pair? + '(1 . 4) + '((5 . 6) + (1 . 5) + (3 . 7) + (4 . 1) + (6 . 2)))) + +(test-equal "no equivalent pair" + #f + (equivalent-pair? + '(1 . 4) + '((5 . 6) + (1 . 5) + (3 . 7) + (6 . 2)))) + +(test-equal "found equivalent pair" + '(1 . 5) + (return-equivalent-pair + '((5 . 6) + (1 . 5) + (3 . 7) + (5 . 1) + (6 . 2)))) + +(test-error "no equivalent pairs" + #t + (return-equivalent-pair + '((5 . 6) + (1 . 5) + (3 . 7) + (6 . 2)))) + +(test-equal "multiply pair 1" + 8 + (multiply-pair (cons 1 8))) + +(test-equal "multiply pair 2" + 24 + (multiply-pair (cons 3 8))) + +(test-equal "task-complete 1" + 1020099 + (rr "1009 237 791 478 1537 1011 1628")) + +(test-equal "task-complete 2" + 514579 + (rr "1721 +979 +366 +299 +675 +1456 +")) + + +(test-end "harness") diff --git a/report-repair/rr.scm b/report-repair/rr.scm new file mode 100644 index 0000000..b327d3c --- /dev/null +++ b/report-repair/rr.scm @@ -0,0 +1,65 @@ +#!/run/current-system/profile/bin/guile \ +-e main -s +!# +(define-module (rr) + #:use-module (srfi srfi-1) + #:use-module (ice-9 exceptions) + #:export (rr + multiply-pair + return-equivalent-pair + equivalent-pair? + return-friendship-pair + report->pairs)) + + +(define (rr str) + (multiply-pair + (return-equivalent-pair + (report->pairs str)))) + +(define (multiply-pair pair) + (* (car pair) + (cdr pair))) + +(define (return-equivalent-pair pairs) + "Given PAIRS friendship pairs, returns the +ones that are found to be friends. Throws +friendship-exception if no friends are found. + +We do NOT care if there are multiple pairs. +Return the first one." + (let loop ((pair (car pairs)) (pairs (cdr pairs))) + (if (null? pairs) + (raise-exception + (make-exception-with-message + "Concerning lack of friendship!")) + (if (equivalent-pair? pair pairs) + pair + (loop (car pairs) (cdr pairs)))))) + +(define (equivalent-pair? pair pairs) + "Given friendship pair PAIR and a list +of other PAIRS, determines if PAIR is +contained in PAIRS, irrespective of order" + (let ((r-pair (cons (cdr pair) + (car pair)))) + (any (lambda (pair) + (equal? r-pair pair)) + pairs))) + +(define (report->pairs str) + "Given a report, convert it to a +list of friendship pairs." + (let ((lst (string-split + (string-trim-both str char-set:whitespace) + char-set:whitespace))) + (map (lambda (str) + (return-friendship-pair + (string->number str))) + lst))) + +(define (return-friendship-pair num) + "Given NUM, returns a cons pair with +CAR as the original number and CDR as +the companion number." + (cons num (- 2020 num))) |