C solution for week 90/part 2.

2 files changed, 55 insertions, 0 deletions

diff --git a/challenge-090/abigail/README b/challenge-090/abigail/README
index 9a1cfc4990..9e71f9a4bd 100644
--- a/challenge-090/abigail/README
+++ b/challenge-090/abigail/README
@@ -7,4 +7,5 @@ Solution by Abigail
     * Perl
 
 * Task 2
+    * C
     * Perl
diff --git a/challenge-090/abigail/c/ch-2.c b/challenge-090/abigail/c/ch-2.c
new file mode 100644
index 0000000000..d1a10d7950
--- /dev/null
+++ b/challenge-090/abigail/c/ch-2.c
@@ -0,0 +1,54 @@
+# include <stdio.h>
+# include <stdlib.h>
+# include <string.h>
+
+/*
+ * For challenge description, see ../perl/ch-2.pl
+ */
+
+char * tick = "\xE2\x9C\x93";   /* UTF-8 bytes for check mark */
+
+/*
+ * Given a number, return the width if printed as a decimal number.
+ */
+int width (long long number) {
+    char string [32];
+    sprintf (string, "%lld", number);
+    return ((int) strlen (string));
+}
+
+int main () {
+    char *  line    = NULL;
+    size_t  len     = 0;
+
+    while (getline (&line, &len, stdin) != -1) {
+        long long A, B, P;
+        if (sscanf (line, "%lld %lld", &A, &B) == 2) {
+            /* Product we will be working towards */
+            P = A * B;
+
+            /* Find the widths */
+            int w_A = width (A);
+            int w_P = width (P);
+
+            /* Main loop */
+            while (A) {
+                printf ("%*lld  %*lld %s\n", w_A, A, w_P, B,
+                                               A % 2 ? tick : "");
+                A = A / 2;
+                B = B * 2;
+            }
+
+            /* Print the horizontal bar */
+            char line [64];
+            sprintf (line, "%*s  %*s +\n", w_A, "", w_P, "");
+            for (int i = 0; i < w_P; i ++) {
+                line [w_A + 2 + i] = '-';
+            }
+            printf ("%s", line);
+
+            /* Print the final line with the product */
+            printf ("%*s  %*lld\n", w_A, "", w_P, P);
+        }
+    }
+}