Implement day 03 part 1.

2019/src/point.hpp

@@ -0,0 +1,62 @@
+#pragma once
+
+#include <array>
+#include <cstdlib>
+#include "utils.hpp"
+
+namespace aoc2019 {
+    template<class T, std::size_t L>
+    class Point : public std::array<T, L> {
+    public:
+        constexpr Point& operator +=(Point other) {
+            for (std::size_t i = 0; i < L; ++i) {
+                (*this)[i] += other[i];
+            }
+            return *this;
+        }
+
+        constexpr Point operator+(Point other) const {
+            auto result = *this;
+            result += other;
+
+            return result;
+        }
+
+        constexpr Point& operator -=(Point other) {
+            for (std::size_t i = 0; i < L; ++i) {
+                (*this)[i] -= other[i];
+            }
+
+            return *this;
+        }
+
+        constexpr Point operator-(Point other) const {
+            auto result = *this;
+            result -= other;
+
+            return result;
+        }
+
+        constexpr T l1() const {
+            T result = 0;
+            for (auto e : *this) {
+                result += std::abs(e);
+            }
+
+            return result;
+        }
+    };
+}
+
+namespace std {
+    // Make point usable with unordered collections.
+    template<class T, std::size_t L> struct hash<aoc2019::Point<T, L>> {
+        size_t operator()(const aoc2019::Point<T, L> &o) const {
+            size_t seed = 0;
+            for (auto i : o) {
+                aoc2019::combine_hash(seed, i);
+            }
+            return seed;
+        }
+    };
+}