2 files changed, 80 insertions, 0 deletions
diff --git a/challenge-110/abigail/README.md b/challenge-110/abigail/README.md
index 051aef0d33..642f4d5bbf 100644
--- a/challenge-110/abigail/README.md
+++ b/challenge-110/abigail/README.md
@@ -43,6 +43,7 @@ can completly ignore any white space in the input.
 ### 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-110/abigail/c/ch-1.c b/challenge-110/abigail/c/ch-1.c
new file mode 100644
index 0000000000..011ef2ee99
--- /dev/null
+++ b/challenge-110/abigail/c/ch-1.c
@@ -0,0 +1,79 @@
+# include <stdlib.h>
+# include <stdio.h>
+# include <string.h>
+# include <ctype.h>
+# include <stdbool.h>
+
+/*
+ * See ../README.md
+ */
+
+/*
+ * Run as: cc -o ch-1.o ch-1.c; ./ch-1.o < input-file
+ */
+
+int main (void) {
+    char *  raw     = NULL;
+    size_t  len     = 0;
+    size_t  str_len;
+
+    while ((str_len = getline (&raw, &len, stdin)) != -1) {
+        /*
+         * Make a copy of line, but without the spaces
+         */
+        char * line;
+        if ((line = (char *) malloc ((str_len + 2) * sizeof (char))) == NULL) {
+            perror ("Malloc failed");
+            exit (1);
+        }
+        char * raw_ptr  = raw;
+        char * line_ptr = line;
+        while (* raw_ptr) {
+            /*
+             * Skip white space
+             */
+            if (isspace (* raw_ptr)) {
+                raw_ptr ++;
+                continue;
+            }
+
+            /*
+             * If the first character is a '+', write two 0s.
+             */
+            if (line_ptr == line && * raw_ptr == '+') {
+                * line_ptr ++ = '0';
+                * line_ptr ++ = '0';
+                raw_ptr ++;
+                continue;
+            }
+            * line_ptr ++ = * raw_ptr ++;
+        }
+        * line_ptr = '\0';
+        /*
+         * If the first character is a '(', and the fourth is a ')',
+         * replace both of them with 0
+         */
+        if (line [0] == '(' && line [3] == ')') {
+            line [0] = '0';
+            line [3] = '0';
+        }
+
+        /*
+         * Check that we have exactly 14 digits
+         */
+        bool valid = true;
+        for (size_t i = 0; i < 14 && valid; i ++) {
+            if (!isdigit (line [i])) {
+                valid = false;
+            }
+        }
+        if (valid && line [14] == '\0') {
+            printf ("%s", raw);
+        }
+
+        free (line);
+    }
+    free (raw);
+
+    return (0);
+}