Implement day 1.

2019/inputs/01.txt

@@ -0,0 +1,100 @@
+102777
+107296
+131207
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+99009
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+83121
+87846
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+144801
+88725
+125958
+116869
+119676

2019/src/day01.cpp

@@ -1,10 +1,26 @@
 #include <iostream>
 #include "days.hpp"
 
+static inline int required(int weight) {
+	return weight / 3 - 2;
+}
+
 void aoc2019::day01_part1(std::istream &input, std::ostream &output) {
-	output << "Not implemented\n";
+	int total = 0;
+	for (int current; input >> current;) {
+		total += required(current);
+	}
+
+	output << total << std::endl;
 }
 
 void aoc2019::day01_part2(std::istream &input, std::ostream &output) {
-	output << "Not implemented\n";
+	int total = 0;
+	for (int current; input >> current;) {
+		for (int fuel = required(current); fuel > 0; fuel = required(fuel)) {
+			total += fuel;
+		}
+	}
+
+	output << total << std::endl;
 }