From 4071a7551681a64b730ce66e77d6daa84f61d1ff Mon Sep 17 00:00:00 2001
From: Colin McMillen <colin@semicolin.games>
Date: Tue, 1 Dec 2020 11:04:50 -0500
Subject: [PATCH] read input from file instead of hard-coding

---
 2020/Program.cs |  14 +++-
 2020/day1.txt   | 200 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 211 insertions(+), 3 deletions(-)
 create mode 100644 2020/day1.txt

diff --git a/2020/Program.cs b/2020/Program.cs
index 110e5f4..ea320e1 100644
--- a/2020/Program.cs
+++ b/2020/Program.cs
@@ -1,12 +1,22 @@
 using System;
 using static System.Console;
 using System.Collections.Generic;
+using System.IO;
+using System.Linq;
 using Xunit;
 
 namespace AdventOfCode {
 
   public class Program {
 
+    static string RootDir =
+        Environment.GetEnvironmentVariable("HOME") + "/src/adventofcode/2020/";
+
+    static List<int> ReadInts(string filename) {
+      string[] lines = File.ReadAllLines(filename);
+      return lines.Select(s => int.Parse(s)).ToList();
+    }
+
     static int Day1Part1(List<int> numbers) {
       for (var i = 0; i < numbers.Count; i++) {
         for (var j = i + 1; j < numbers.Count; j++) {
@@ -40,9 +50,7 @@ namespace AdventOfCode {
       var exampleInput = new List<int>() {
         1721, 979, 366, 299, 675, 1456
       };
-      var testInput = new List<int>() {
-        1768, 1847, 1905, 1713, 1826, 1846, 1824, 1976, 1687, 1867, 1665, 1606, 1946, 1886, 1858, 346, 1739, 1752, 1700, 1922, 1865, 1609, 1617, 1932, 1346, 1213, 1933, 834, 1598, 1191, 1979, 1756, 1216, 1820, 1792, 1537, 1341, 1390, 1709, 1458, 1808, 1885, 1679, 1977, 1869, 1614, 1938, 1622, 1868, 1844, 1969, 1822, 1510, 1994, 1337, 1883, 1519, 1766, 1554, 1825, 1828, 1972, 1380, 1878, 1345, 1469, 1794, 1898, 1805, 1911, 1913, 1910, 1318, 1862, 1921, 1753, 1823, 1896, 1316, 1381, 1430, 1962, 1958, 1702, 1923, 1993, 1789, 2002, 1788, 1970, 1955, 1887, 1870, 225, 1696, 1975, 699, 294, 1605, 1500, 1777, 1750, 1857, 1540, 1329, 1974, 1947, 1516, 1925, 1945, 350, 1669, 1775, 1536, 1871, 1917, 1249, 1971, 2009, 1585, 1986, 1701, 1832, 1754, 1195, 1697, 1941, 1919, 2006, 1667, 1816, 1765, 1631, 2003, 1861, 1000, 1791, 1786, 1843, 1939, 1951, 269, 1790, 1895, 1355, 1833, 1466, 1998, 1806, 1881, 1234, 1856, 1619, 1727, 1874, 1877, 195, 1783, 1797, 2010, 1764, 1863, 1852, 1841, 1892, 1562, 1650, 1942, 1695, 1730, 1965, 1632, 1981, 1900, 1991, 1884, 1278, 1062, 1394, 1999, 2000, 1827, 1873, 1926, 1434, 1802, 1579, 1879, 1671, 1549, 1875, 1838, 1338, 1864, 1718, 1800, 1928, 1749, 1990, 1705,
-      };
+      var testInput = ReadInts(RootDir + "day1.txt");
 
       Assert.Throws<ArgumentException>(() => Day1Part1(emptyInput));
       Assert.Throws<ArgumentException>(() => Day1Part1(bogusInput));
diff --git a/2020/day1.txt b/2020/day1.txt
new file mode 100644
index 0000000..7346cba
--- /dev/null
+++ b/2020/day1.txt
@@ -0,0 +1,200 @@
+1768
+1847
+1905
+1713
+1826
+1846
+1824
+1976
+1687
+1867
+1665
+1606
+1946
+1886
+1858
+346
+1739
+1752
+1700
+1922
+1865
+1609
+1617
+1932
+1346
+1213
+1933
+834
+1598
+1191
+1979
+1756
+1216
+1820
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+1537
+1341
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+1709
+1458
+1808
+1885
+1679
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+1869
+1614
+1938
+1622
+1868
+1844
+1969
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+1510
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+1337
+1883
+1519
+1766
+1554
+1825
+1828
+1972
+1380
+1878
+1345
+1469
+1794
+1898
+1805
+1911
+1913
+1910
+1318
+1862
+1921
+1753
+1823
+1896
+1316
+1381
+1430
+1962
+1958
+1702
+1923
+1993
+1789
+2002
+1788
+1970
+1955
+1887
+1870
+225
+1696
+1975
+699
+294
+1605
+1500
+1777
+1750
+1857
+1540
+1329
+1974
+1947
+1516
+1925
+1945
+350
+1669
+1775
+1536
+1871
+1917
+1249
+1971
+2009
+1585
+1986
+1701
+1832
+1754
+1195
+1697
+1941
+1919
+2006
+1667
+1816
+1765
+1631
+2003
+1861
+1000
+1791
+1786
+1843
+1939
+1951
+269
+1790
+1895
+1355
+1833
+1466
+1998
+1806
+1881
+1234
+1856
+1619
+1727
+1874
+1877
+195
+1783
+1797
+2010
+1764
+1863
+1852
+1841
+1892
+1562
+1650
+1942
+1695
+1730
+1965
+1632
+1981
+1900
+1991
+1884
+1278
+1062
+1394
+1999
+2000
+1827
+1873
+1926
+1434
+1802
+1579
+1879
+1671
+1549
+1875
+1838
+1338
+1864
+1718
+1800
+1928
+1749
+1990
+1705