C code for challenge 69 task 1

1 files changed, 52 insertions, 0 deletions

diff --git a/challenge-069/walt-mankowski/c/ch-1.c b/challenge-069/walt-mankowski/c/ch-1.c
new file mode 100644
index 0000000000..a5e15845c6
--- /dev/null
+++ b/challenge-069/walt-mankowski/c/ch-1.c
@@ -0,0 +1,52 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+const size_t min(const size_t a, const size_t b) {
+    return a <= b ? a : b;
+}
+
+int is_strobogrammatic(const long long n) {
+    char s[20];
+    sprintf(s, "%lld", n);
+    const size_t len = strlen(s);
+    for (size_t i = 0; i < min(len/2+1, len); i++) {
+        const size_t j = len-1-i;
+        switch (s[i]) {
+        case '0':
+            if (s[j] != '0')
+                return 0;
+            break;
+        case '1':
+            if (s[j] != '1')
+                return 0;
+            break;
+        case '6':
+            if (s[j] != '9')
+                return 0;
+            break;
+        case '8':
+            if (s[j] != '8')
+                return 0;
+            break;
+        case '9':
+            if (s[j] != '6')
+                return 0;
+            break;
+        default:
+            return 0;
+        }
+    }
+    return 1;
+}
+
+int main(int argc, char *argv[]) {
+    const long long A = atoll(argv[1]);
+    const long long B = atoll(argv[2]);
+
+    for (long long i = A; i <= B; i++)
+        if (is_strobogrammatic(i))
+            printf("%lld\n", i);
+
+    return 0;
+}