C solution for week 103, part 1

2 files changed, 58 insertions, 0 deletions

diff --git a/challenge-103/abigail/README.md b/challenge-103/abigail/README.md
index ee507a9b99..e59555b95d 100644
--- a/challenge-103/abigail/README.md
+++ b/challenge-103/abigail/README.md
@@ -51,6 +51,7 @@ output.
 ### Solutions
 * [AWK](awk/ch-1.awk)
 * [Bash](bash/ch-1.sh)
+* [C](c/ch-1.c)
 * [Perl](perl/ch-1.pl)
 
 ### Blog
diff --git a/challenge-103/abigail/c/ch-1.c b/challenge-103/abigail/c/ch-1.c
new file mode 100644
index 0000000000..f4974ced54
--- /dev/null
+++ b/challenge-103/abigail/c/ch-1.c
@@ -0,0 +1,57 @@
+# include <stdlib.h>
+# include <stdio.h>
+# include <string.h>
+
+/*
+ * See ../README.md
+ */
+
+/*
+ * Run as: cc -o ch-1.o ch-1.c; ./ch-1.o < input-file
+ */
+
+/*
+ * We're reading years from standard input, one year per line, outputting
+ * years from the sexagenary cycle [1]. This is slightly more than what
+ * the challenge ask; the challenge asks to output the heavenly stem [2],
+ * and the earthly branch [3]. But we also output its Yin/Yang.
+ *
+ * [1] https://en.wikipedia.org/wiki/Sexagenary_cycle
+ * [2] https://en.wikipedia.org/wiki/Heavenly_Stems
+ * [3] https://en.wikipedia.org/wiki/Earthly_Branches
+ *
+
+ *
+ * Each of the cycles have been rotated so the first entry corresponds to
+ * the year 0 in the Proleptic Gregorian calendar. (We're using the
+ * convention of having a year 0, as per ISO 8601).
+ * That way, we can just mod the year with the number of entries, without
+ * first having to subtract something from the year.
+ *
+ * The heavenly stems last for 2 years, so we just duplicate the entries.
+ */
+
+char * yin_yang         [ 2] = {"Yang",   "Yin"};
+size_t yin_yang_size         =   2;
+char * heavenly_stems   [10] = {"Metal",  "Metal",   "Water", "Water",
+                                "Wood",   "Wood",    "Fire",  "Fire",
+                                "Earth",  "Earth"};
+size_t heavenly_stems_size   =  10;
+char * earthly_branches [12] = {"Monkey", "Rooster", "Dog",   "Pig",
+                                "Rat",    "Ox",      "Tiger", "Rabbit",
+                                "Dragon", "Snake",   "Horse", "Goat"};
+size_t earthly_branches_size =  12;
+
+
+
+int main (void) {
+    int year;
+
+    while (scanf ("%d", &year) == 1) {
+        printf ("%s %s %s\n", yin_yang         [year % yin_yang_size],
+                              heavenly_stems   [year % heavenly_stems_size],
+                              earthly_branches [year % earthly_branches_size]);
+    }
+
+    return (0);
+}