day01, advent of code 2022

1 files changed, 73 insertions, 0 deletions

diff --git a/2022/src/day01.cpp b/2022/src/day01.cpp
new file mode 100644
index 0000000..ece0309
--- /dev/null
+++ b/2022/src/day01.cpp
@@ -0,0 +1,73 @@
+#include <fstream>
+#include <iostream>
+#include <numeric>
+#include <sstream>
+#include <string>
+#include <vector>
+using namespace std;
+
+string
+read_file(string_view filename)
+{
+        fstream input{ filename };
+        return { istreambuf_iterator<char>{ input }, {} };
+}
+
+vector<string>
+split(string_view line, string_view delimiter)
+{
+        string::size_type pos_start = 0;
+        string::size_type pos_end   = 0;
+
+        vector<string> result;
+
+        while ( (pos_end = line.find(delimiter, pos_start)) != string::npos ) {
+                result.emplace_back(line.substr(pos_start, pos_end - pos_start));
+                pos_start = pos_end + delimiter.length();
+        }
+
+        if ( pos_start != line.size() ) {
+                result.emplace_back(line.substr(pos_start));
+        }
+
+        return result;
+}
+
+vector<long>
+split(const string& line)
+{
+        stringstream input{ line };
+        return { istream_iterator<long>(input), {} };
+}
+
+void
+part1(const vector<string>& parts)
+{
+        long max_so_far = 0;
+        for ( const auto& part: parts ) {
+                const auto nums = split(part);
+                max_so_far      = max(accumulate(begin(nums), end(nums), 0L), max_so_far);
+        }
+        cout << max_so_far << endl;
+}
+
+void
+part2(const vector<string>& parts)
+{
+        vector<long> all;
+        for ( const auto& part: parts ) {
+                const auto nums = split(part);
+                all.emplace_back(accumulate(begin(nums), end(nums), 0L));
+        }
+        sort(begin(all), end(all), greater<>());
+        cout << all[0] + all[1] + all[2] << endl;
+}
+
+int
+main()
+{
+        const auto line  = read_file("data/day01.txt");
+        const auto parts = split(line, "\n\n");
+        part1(parts);
+        part2(parts);
+}