day13

1 files changed, 30 insertions, 0 deletions

diff --git a/day13.cc b/day13.cc
new file mode 100644
index 0000000..91fb5c6
--- /dev/null
+++ b/day13.cc
@@ -0,0 +1,30 @@
+#include <algorithm>
+#include <functional>
+#include <iostream>
+#include <numeric>
+#include <vector>
+
+using namespace std;
+using namespace std::placeholders;
+
+struct scanner {
+	int d, r;
+	bool hit(int delay=0) { return (d + delay) % (2*r - 2) == 0; }
+	operator int() { return hit() ? d * r : 0; }
+};
+
+int main()
+{
+	vector<scanner> ss;
+	char _;
+	for (int d, r; cin >> d >> _ >> r; )
+		ss.push_back({d, r});
+
+	cout << std::accumulate(begin(ss), end(ss), 0) << endl;
+
+	for (int d = 0; ; d++)
+		if (none_of(ss.begin(), ss.end(), bind(&scanner::hit, _1, d))) {
+			cout << d << endl;
+			break;
+		}
+}