2019 day1

1 files changed, 45 insertions, 1 deletions

diff --git a/src/2019/day1/aoc.cpp b/src/2019/day1/aoc.cpp
index 26fed89..933228d 100644
--- a/src/2019/day1/aoc.cpp
+++ b/src/2019/day1/aoc.cpp
@@ -1,3 +1,47 @@
 #include "aoc.h"
 
-namespace aoc2019 {}
+namespace aoc2019 {
+
+int parse_day1(line_view lv) {
+  int d{0};
+  const char* p = lv.line;
+  while (*p >= '0' && *p <= '9') {
+    d = d * 10 + *p - '0';
+    p++;
+  }
+  return d;
+}
+
+int day1(line_view file) {
+  int fuel{0};
+  auto cal = [](int m) -> int { return m / 3 - 2; };
+  per_line(file, [&fuel, &cal](line_view lv) {
+    fuel += cal(parse_day1(lv));
+    return true;
+  });
+
+  return fuel;
+}
+
+void add_fuel(int base, int* total) {
+  if (base > 0) {
+    // printf("%d\n", base);
+    *total += base;
+    add_fuel(base / 3 - 2, total);
+  }
+}
+
+int day1part2(line_view file) {
+  int fuel{0};
+  per_line(file, [&fuel](line_view lv) {
+    int total{0};
+    int base = parse_day1(lv);
+    add_fuel(base / 3 - 2, &total);
+    fuel += total;
+    return true;
+  });
+
+  return fuel;
+}
+
+} // namespace aoc2019