commit f57316c89ce6c31a7e9571492690c071c820c001
Author: aabacchus <bvnfuller@gmail.com>
Date: Mon, 22 Nov 2021 16:38:28 +0000
2020 day 1 part 1
Diffstat:
| A | 2020/01/01.c | | | 63 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
| A | 2020/01/input | | | 200 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
2 files changed, 263 insertions(+), 0 deletions(-)
diff --git a/2020/01/01.c b/2020/01/01.c
@@ -0,0 +1,63 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+void
+usage(char *argv0) {
+ printf("usage: %s TARGET < input.file\n", argv0);
+}
+
+int
+main(int argc, char **argv) {
+ if (argc < 2) {
+ usage(*argv);
+ return 1;
+ }
+
+ int target = atoi(argv[1]);
+ if (target == 0) {
+ fprintf(stderr, "error parsing target '%s'\n", argv[1]);
+ return 1;
+ }
+
+ /* buffer for each line */
+ char buf[100] = {'\0'};
+
+ size_t nums_len = 200;
+ int *nums = malloc(sizeof(int) * nums_len);
+ if (nums == NULL) {
+ perror("malloc");
+ return 1;
+ }
+ int *n = nums;
+
+ while (fgets(buf, 100, stdin) != NULL) {
+ *n++ = atoi(buf);
+ size_t offset = n - nums;
+ if (offset > nums_len) {
+ nums_len += 10;
+ int *tmp = realloc(nums, sizeof(int) * nums_len);
+ if (tmp == NULL) {
+ perror("realloc");
+ goto error_free_nums;
+ }
+
+ nums = tmp;
+ n = nums + offset;
+ }
+ }
+
+ for (size_t i = 0; i < nums_len; i++) {
+ for (size_t j = i + 1; j < nums_len; j++) {
+ if (nums[i] + nums[j] == target) {
+ printf("%d * %d = %d\n", nums[i], nums[j], nums[i] * nums[j]);
+ goto end;
+ }
+ }
+ }
+end:
+ free(nums);
+ return 0;
+error_free_nums:
+ free(nums);
+ return 1;
+}
diff --git a/2020/01/input b/2020/01/input
@@ -0,0 +1,200 @@
+1630
+1801
+1917
+1958
+1953
+1521
+1990
+1959
+1543
+1798
+638
+1499
+1977
+1433
+1532
+1780
+1559
+1866
+1962
+1999
+1623
+1772
+1730
+1670
+1791
+1947
+1961
+1523
+959
+1998
+1693
+1490
+1712
+910
+1635
+1837
+586
+1590
+1741
+1739
+1660
+1883
+1777
+1734
+1413
+1456
+1511
+1957
+1738
+1685
+1677
+1419
+1566
+1639
+1578
+1922
+1856
+1946
+1965
+1649
+1854
+1610
+1806
+1424
+1616
+218
+1678
+1992
+1985
+903
+1626
+1412
+1964
+671
+1692
+1571
+1690
+1587
+1933
+1367
+1585
+1575
+498
+1601
+2005
+1711
+1948
+1991
+1580
+1704
+207
+1560
+1867
+1600
+1594
+1930
+1541
+1832
+1613
+1599
+1757
+71
+1534
+1940
+1982
+1960
+1530
+1908
+1857
+1410
+1987
+1526
+1546
+2002
+1923
+1972
+1752
+1984
+1754
+1916
+1942
+1980
+1608
+1398
+1438
+1955
+1968
+1799
+1976
+1847
+1775
+1904
+1983
+1945
+1554
+1486
+1527
+1884
+1553
+1736
+1561
+1513
+1695
+1431
+1997
+1405
+1872
+1434
+1679
+1609
+105
+1582
+1795
+1826
+1886
+1472
+2007
+1617
+1978
+1669
+1764
+1865
+1773
+1993
+1666
+1583
+2009
+1969
+2001
+1659
+1833
+1713
+1893
+2000
+1520
+1652
+1437
+1556
+1633
+1386
+1819
+1973
+1426
+1975
+2010
+1863
+1593
+1996
+1796
+1986
+1995
+657
+1784
+1644
+1941
+1596
+1849
+1065
+1927
+1525
