Initial set-up for 2019 AoC.

2019/src/day01.cpp

@@ -0,0 +1,35 @@
+#include <numeric>
+#include <iterator>
+#include <vector>
+#include <unordered_set>
+#include "solutions.hpp"
+
+// Currently an implementation of 2018 day 1
+void aoc2019::day01_part1(std::istream &input, std::ostream &output) {
+    int sum = std::accumulate(std::istream_iterator<int>(input),
+                              std::istream_iterator<int>(),
+                              0);
+
+    output << sum << std::endl;
+}
+
+void aoc2019::day01_part2(std::istream &input, std::ostream &output) {
+    std::vector<int> drifts;
+    std::copy(std::istream_iterator<int>(input),
+              std::istream_iterator<int>(),
+              std::back_inserter(drifts));
+
+    int cur = 0;
+    std::unordered_set<int> seen{cur};
+    while (true) {
+        for (auto drift : drifts) {
+            cur += drift;
+            if (seen.count(cur) == 1) {
+                output << drift << std::endl;
+                return;
+            } else {
+                seen.insert(cur);
+            }
+        }
+    }
+}