aoc 2025, day 7 (clean up)

1 files changed, 10 insertions, 18 deletions

diff --git a/2025/src/day07.cpp b/2025/src/day07.cpp
index e902a43..6592518 100644
--- a/2025/src/day07.cpp
+++ b/2025/src/day07.cpp
@@ -14,21 +14,14 @@ namespace {
 vector<string>
 read_file(const filesystem::path& filename)
 {
-        ifstream       file{ filename };
-        vector<string> grid;
-
-        for ( string line; getline(file, line); ) {
-                grid.emplace_back(line);
-        }
-
-        return grid;
+        ifstream file{ filename };
+        return { istream_iterator<string>{ file }, {} };
 }
 
 void
 part1(const vector<string>& grid)
 {
-        set<size_t> curr;
-        curr.insert(grid[0].find('S'));
+        set<size_t> curr{ grid[0].find('S') };
 
         int count = 0;
         for ( size_t i = 1; i < grid.size(); ++i ) {
@@ -36,11 +29,10 @@ part1(const vector<string>& grid)
 
                 auto next = curr;
 
-                for ( const auto pos: curr ) {
-                        if ( row[pos] == '^' ) {
-                                next.erase(pos);
-                                next.insert(pos - 1);
-                                next.insert(pos + 1);
+                for ( const auto col: curr ) {
+                        if ( row[col] == '^' ) {
+                                next.erase(col);
+                                next.insert({ col - 1, col + 1 });
                                 ++count;
                         }
                 }
@@ -55,7 +47,8 @@ part2(const vector<string>& grid)
 {
         using Pos = tuple<size_t, size_t>;
 
-        map<Pos, long>             cache;
+        map<Pos, long> cache;
+
         function<long(const Pos&)> walk = [&](const Pos& pos) {
                 if ( cache.contains(pos) ) {
                         return cache.at(pos);
@@ -77,8 +70,7 @@ part2(const vector<string>& grid)
                 return (cache[pos] = walk({ col, row + 1 }));
         };
 
-        const auto col = grid[0].find('S');
-        cout << "Part 2: " << walk(Pos{ col, 0 }) << '\n';
+        cout << "Part 2: " << walk(Pos{ grid[0].find('S'), 0 }) << '\n';
 }
 
 } // namespace