Add solved exercises

1 files changed, 17 insertions, 0 deletions

diff --git a/c/armstrong-numbers/src/armstrong_numbers.c b/c/armstrong-numbers/src/armstrong_numbers.c
new file mode 100644
index 0000000..8c0edfd
--- /dev/null
+++ b/c/armstrong-numbers/src/armstrong_numbers.c
@@ -0,0 +1,17 @@
+#include <math.h>
+#include "armstrong_numbers.h"
+
+bool is_armstrong_number(unsigned int num) {
+    // log10(0) returns `HUGE_VAL' or `-∞'.
+    if (!num) return true;
+
+    unsigned short len = log10(num) + 1;
+    unsigned int arms = 0, num_cp = num;
+
+    for (; num != 0; num /= 10) {
+        unsigned short rem = num % 10;
+        arms += pow(rem, len);
+    }
+
+    return num_cp == arms;
+}