commit a38ef507e5885d4432a0cf981cd712783aff33a3
Author: Johannes Loher <johannes.loher@fg4f.de>
Date:   Tue Dec 1 10:43:51 2020 +0100

    solve day1 part1 and part2

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..21c2e29
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,28 @@
+
+# Compiled Object files
+*.o
+*.obj
+
+# Compiled Dynamic libraries
+*.so
+*.dylib
+*.dll
+
+# Compiled Static libraries
+*.a
+*.lib
+
+# Executables
+*.exe
+
+# DUB
+.dub
+docs.json
+__dummy.html
+docs/
+
+# Code coverage
+*.lst
+
+# Main binaries
+main
\ No newline at end of file
diff --git a/day1/part1/input b/day1/part1/input
new file mode 100644
index 0000000..a0657be
--- /dev/null
+++ b/day1/part1/input
@@ -0,0 +1,200 @@
+1935
+1956
+1991
+1425
+1671
+1537
+1984
+1569
+1873
+1840
+1720
+1937
+1823
+1625
+1727
+1812
+1714
+1900
+1939
+1931
+1951
+1756
+1942
+1611
+1979
+1930
+1996
+2000
+1544
+1780
+1687
+1760
+1836
+1814
+1691
+1817
+1964
+1899
+1577
+1547
+866
+1560
+1988
+1601
+1970
+1738
+1507
+1667
+1851
+1933
+1515
+1856
+1969
+1860
+1801
+2007
+1866
+1800
+1749
+1843
+1711
+1495
+1905
+763
+1672
+1858
+1987
+1492
+1849
+1993
+1737
+1874
+1658
+1810
+1665
+1768
+1950
+1879
+1816
+1868
+1995
+1763
+1783
+1833
+1968
+1847
+1748
+1725
+1891
+1755
+286
+1976
+1977
+1655
+1808
+1986
+1779
+1861
+1953
+1888
+1792
+1811
+1872
+1790
+1839
+1985
+1827
+1842
+1925
+1735
+1635
+1821
+1820
+1973
+1531
+1770
+59
+1846
+1932
+1907
+1730
+933
+1395
+1753
+1751
+361
+1530
+1782
+1087
+1589
+1929
+1795
+1815
+1732
+1765
+1877
+1722
+526
+1709
+1789
+1892
+1913
+1662
+1809
+1670
+1947
+1835
+1587
+1758
+1982
+2009
+1757
+670
+1983
+1524
+1878
+1796
+1952
+566
+1922
+1882
+1870
+1799
+1731
+1724
+1805
+2003
+1596
+1566
+1853
+1911
+1857
+1739
+1744
+1627
+1729
+1745
+1845
+1582
+1884
+1883
+1941
+1764
+1685
+1791
+1837
+1697
+1742
+1781
+1948
+1876
+1989
+1643
+1871
+1906
+1726
+1958
+1502
+1927
+1946
diff --git a/day1/part1/main.d b/day1/part1/main.d
new file mode 100644
index 0000000..2535b15
--- /dev/null
+++ b/day1/part1/main.d
@@ -0,0 +1,32 @@
+import std;
+
+void main()
+{
+    File("input", "r").byLine.map!(to!int).array.multiply2EntriesThatSumTo(2020).writeln;
+}
+
+int multiply2EntriesThatSumTo(int[] input, int sum)
+{
+    foreach (key1; input)
+    {
+        foreach (key2; input)
+        {
+            if (key2 == key1)
+            {
+                continue;
+            }
+            if (key1 + key2 == sum)
+            {
+                return key1 * key2;
+            }
+        }
+    }
+    return 0;
+}
+
+unittest
+{
+    auto input = [1721, 979, 366, 299, 675, 1456];
+
+    assert(input.multiply2EntriesThatSumTo(2020) == 514579);
+}
diff --git a/day1/part2/input b/day1/part2/input
new file mode 100644
index 0000000..a0657be
--- /dev/null
+++ b/day1/part2/input
@@ -0,0 +1,200 @@
+1935
+1956
+1991
+1425
+1671
+1537
+1984
+1569
+1873
+1840
+1720
+1937
+1823
+1625
+1727
+1812
+1714
+1900
+1939
+1931
+1951
+1756
+1942
+1611
+1979
+1930
+1996
+2000
+1544
+1780
+1687
+1760
+1836
+1814
+1691
+1817
+1964
+1899
+1577
+1547
+866
+1560
+1988
+1601
+1970
+1738
+1507
+1667
+1851
+1933
+1515
+1856
+1969
+1860
+1801
+2007
+1866
+1800
+1749
+1843
+1711
+1495
+1905
+763
+1672
+1858
+1987
+1492
+1849
+1993
+1737
+1874
+1658
+1810
+1665
+1768
+1950
+1879
+1816
+1868
+1995
+1763
+1783
+1833
+1968
+1847
+1748
+1725
+1891
+1755
+286
+1976
+1977
+1655
+1808
+1986
+1779
+1861
+1953
+1888
+1792
+1811
+1872
+1790
+1839
+1985
+1827
+1842
+1925
+1735
+1635
+1821
+1820
+1973
+1531
+1770
+59
+1846
+1932
+1907
+1730
+933
+1395
+1753
+1751
+361
+1530
+1782
+1087
+1589
+1929
+1795
+1815
+1732
+1765
+1877
+1722
+526
+1709
+1789
+1892
+1913
+1662
+1809
+1670
+1947
+1835
+1587
+1758
+1982
+2009
+1757
+670
+1983
+1524
+1878
+1796
+1952
+566
+1922
+1882
+1870
+1799
+1731
+1724
+1805
+2003
+1596
+1566
+1853
+1911
+1857
+1739
+1744
+1627
+1729
+1745
+1845
+1582
+1884
+1883
+1941
+1764
+1685
+1791
+1837
+1697
+1742
+1781
+1948
+1876
+1989
+1643
+1871
+1906
+1726
+1958
+1502
+1927
+1946
diff --git a/day1/part2/main.d b/day1/part2/main.d
new file mode 100644
index 0000000..2050e61
--- /dev/null
+++ b/day1/part2/main.d
@@ -0,0 +1,39 @@
+import std;
+
+void main()
+{
+    File("input", "r").byLine.map!(to!int).array.multiply3EntriesThatSumTo(2020).writeln;
+}
+
+int multiply3EntriesThatSumTo(int[] input, int sum)
+{
+    foreach (key1; input)
+    {
+        foreach (key2; input)
+        {
+            if (key2 == key1)
+            {
+                continue;
+            }
+            foreach (key3; input)
+            {
+                if (key3 == key1 || key3 == key2)
+                {
+                    continue;
+                }
+                if (key1 + key2 + key3 == sum)
+                {
+                    return key1 * key2 * key3;
+                }
+            }
+        }
+    }
+    return 0;
+}
+
+unittest
+{
+    auto input = [1721, 979, 366, 299, 675, 1456];
+
+    assert(input.multiply3EntriesThatSumTo(2020) == 241_861_950);
+}