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-rw-r--r--3/part1.c35
1 files changed, 35 insertions, 0 deletions
diff --git a/3/part1.c b/3/part1.c
new file mode 100644
index 0000000..19f3bf3
--- /dev/null
+++ b/3/part1.c
@@ -0,0 +1,35 @@
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define INC_RIGHT 3
+
+int count_trees(const char * filename)
+{
+ FILE * file = fopen(filename, "r");
+
+ // Include space for newline and string terminator
+ char buffer[64] = { 0 };
+ // Start is always safe
+ fgets(buffer, 64, file);
+ // strlen includes the newline
+ int width = strchr(buffer, '\n') - buffer;
+
+ int pos = INC_RIGHT;
+ int hit = 0;
+ while (fgets(buffer, 64, file)) {
+ if (buffer[pos] == '#') {
+ hit++;
+ }
+
+ pos = (pos + INC_RIGHT) % width;
+ }
+
+ return hit;
+}
+
+int main()
+{
+ printf("%i", count_trees("input"));
+}