aoc 2016, day 3

2 files changed, 57 insertions, 1 deletions

diff --git a/2016/src/day02.cpp b/2016/src/day02.cpp
index ad625d5..612de28 100644
--- a/2016/src/day02.cpp
+++ b/2016/src/day02.cpp
@@ -13,7 +13,6 @@ read_file(string_view filename)
         fstream        input{ filename };
         vector<string> lines;
 
-        vector<tuple<char, long>> result;
         for ( string line; getline(input, line); ) {
                 lines.emplace_back(line);
         }
diff --git a/2016/src/day03.cpp b/2016/src/day03.cpp
new file mode 100644
index 0000000..fad26b8
--- /dev/null
+++ b/2016/src/day03.cpp
@@ -0,0 +1,57 @@
+#include <array>
+#include <fstream>
+#include <iostream>
+#include <sstream>
+#include <string>
+#include <vector>
+
+using namespace std;
+
+vector<array<long, 3>>
+read_file(string_view filename)
+{
+        fstream                input{ filename };
+        vector<array<long, 3>> result;
+
+        for ( string line; getline(input, line); ) {
+                stringstream sstr{ line };
+                vector<long> nums{ istream_iterator<long>{ sstr }, {} };
+
+                result.push_back({ nums.at(0), nums.at(1), nums.at(2) });
+        }
+
+        return result;
+}
+
+bool
+is_triangle(array<long, 3> set)
+{
+        ranges::sort(set);
+        return set[0] + set[1] > set[2];
+}
+
+void
+part1(const vector<array<long, 3>>& data)
+{
+        cout << ranges::count_if(data, is_triangle) << endl;
+}
+
+void
+part2(const vector<array<long, 3>>& data)
+{
+        long sum = 0;
+        for ( size_t row = 0; row < data.size(); row += 3 ) {
+                sum += is_triangle({ data[row][0], data[row + 1][0], data[row + 2][0] }) ? 1 : 0;
+                sum += is_triangle({ data[row][1], data[row + 1][1], data[row + 2][1] }) ? 1 : 0;
+                sum += is_triangle({ data[row][2], data[row + 1][2], data[row + 2][2] }) ? 1 : 0;
+        }
+        cout << sum << endl;
+}
+
+int
+main()
+{
+        auto data = read_file("data/day03.txt");
+        part1(data);
+        part2(data);
+}