day1 and day2

Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "aoc"
+version = "0.1.0"
+authors = ["Glenn Griffin <ggriffiniii@gmail.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+aoc-runner = "0.3.0"
+aoc-runner-derive = "0.3.0"

input/2020/day1.txt

@@ -0,0 +1,200 @@
+1782
+1344
+1974
+1874
+1800
+1973
+1416
+1952
+1982
+1506
+1642
+1514
+1978
+1895
+1747
+1564
+1398
+1683
+1886
+1492
+1629
+1433
+295
+1793
+1740
+1852
+1697
+1471
+1361
+1751
+1426
+2004
+1763
+1663
+1742
+1666
+1733
+1880
+1600
+1723
+1478
+1912
+1820
+1615
+1875
+1547
+1554
+752
+1905
+1368
+954
+1425
+1391
+691
+1835
+744
+1850
+1713
+1995
+1926
+1817
+1774
+1986
+2010
+1427
+1609
+1927
+1362
+1420
+1722
+1590
+1925
+1617
+1434
+1826
+1636
+1687
+1946
+704
+1797
+1517
+1801
+1865
+1963
+1828
+1829
+1955
+1832
+1987
+1585
+1646
+1575
+1351
+1345
+1729
+1933
+1918
+1902
+1490
+1627
+1370
+1650
+1340
+1539
+1588
+1715
+1573
+1384
+1403
+1673
+1750
+1578
+1831
+1849
+1719
+1359
+2008
+1837
+1958
+480
+1388
+1770
+1999
+1066
+1730
+1541
+1802
+1962
+1891
+1816
+1505
+1665
+1551
+1954
+1378
+1998
+1612
+1544
+1953
+1502
+1888
+1655
+1614
+1903
+1675
+1498
+1653
+1769
+1863
+1607
+1945
+1651
+1558
+1777
+1460
+1711
+1677
+1988
+1441
+1821
+1867
+1656
+1731
+1885
+1482
+1439
+1990
+1809
+1794
+1951
+1858
+1969
+509
+1486
+1971
+1557
+1896
+1884
+1834
+1814
+1216
+1997
+1966
+1808
+1754
+1804
+1684
+2001
+1699
+1781
+1429
+1322
+1603
+1596
+1823
+1700
+1552
+1352
+1621
+1669

src/lib.rs

@@ -0,0 +1,75 @@
+use aoc_runner_derive::{aoc_lib, aoc};
+
+#[aoc(day1, part1)]
+pub fn solve_d1_p1(input: &str) -> u64 {
+    let mut entries: Vec<u64> = input.split('\n').map(|x| x.parse().unwrap()).collect();
+    entries.sort();
+    for entry in &entries {
+        let needed = 2020 - entry;
+        if let Ok(idx) = entries.binary_search(&needed) {
+            return entry * entries[idx];
+        }
+    }
+    panic!("not found");
+}
+
+#[aoc(day1, part2)]
+pub fn solve_d1_p2(input: &str) -> Option<u64> {
+    let mut entries: Vec<u64> = input.split('\n').map(|x| x.parse().unwrap()).collect();
+    entries.sort();
+    for i in 0 .. entries.len()-2 {
+        let entry1 = entries[i];
+        for j in i+1 .. entries.len()-1 {
+            let entry2 = entries[j];
+            if entry1 + entry2 > 2020 {
+                break;
+            }
+            for k in j+1 .. entries.len() {
+                let entry3 = entries[k];
+                if entry1 + entry2 + entry3 == 2020 {
+                    return Some(entry1 * entry2 * entry3)
+                }
+            }
+        }
+    }
+    return None
+}
+
+#[aoc(day2, part1)]
+pub fn solve_d2_p1(input: &str) -> usize {
+    fn line_is_valid(mut line: &str) -> bool {
+        let lb_idx = line.find('-').unwrap();
+        let lb: usize = (&line[..lb_idx]).parse().unwrap();
+        line = &line[lb_idx+1..];
+
+        let ub_idx = line.find(' ').unwrap();
+        let ub: usize = (&line[..ub_idx]).parse().unwrap();
+        line = &line[ub_idx+1..];
+
+        let letter = line.as_bytes()[0];
+        let passwd = &line[3..];
+        let count = passwd.bytes().filter(|&b| b == letter).count();
+        count >= lb && count <= ub
+    }
+    input.split('\n').filter(|x| line_is_valid(x)).count()
+}
+
+#[aoc(day2, part2)]
+pub fn solve_d2_p2(input: &str) -> usize {
+    fn line_is_valid(mut line: &str) -> bool {
+        let lb_idx = line.find('-').unwrap();
+        let lb: usize = (&line[..lb_idx]).parse().unwrap();
+        line = &line[lb_idx+1..];
+
+        let ub_idx = line.find(' ').unwrap();
+        let ub: usize = (&line[..ub_idx]).parse().unwrap();
+        line = &line[ub_idx+1..];
+
+        let letter = line.as_bytes()[0];
+        let passwd = &line[3..].as_bytes();
+        (passwd[lb-1] == letter) ^ (passwd[ub-1] == letter)
+    }
+    input.split('\n').filter(|x| line_is_valid(x)).count()
+}
+
+aoc_lib!{ year = 2020 }