1 files changed, 31 insertions, 3 deletions

diff --git a/2025/src/day05.cpp b/2025/src/day05.cpp
index 2322948..ee565a3 100644
--- a/2025/src/day05.cpp
+++ b/2025/src/day05.cpp
@@ -26,10 +26,10 @@ read_file(const filesystem::path& filename)
 
         for ( string line; getline(file, line); ) {
                 smatch match;
-                if ( regex_search(line, match, range) ) {
+                if ( regex_match(line, match, range) ) {
                         ranges.emplace_back(stol(match[1]), stol(match[2]));
                 }
-                else if ( regex_search(line, match, single) ) {
+                else if ( regex_match(line, match, single) ) {
                         numbers.emplace_back(stol(match[1]));
                 }
         }
@@ -43,7 +43,7 @@ part1(const Ranges& ranges, const vector<long>& numbers)
         long count = 0;
         for ( const auto number: numbers ) {
                 for ( const auto [start, end]: ranges ) {
-                        if ( number >= start && number <= end ) {
+                        if ( start <= number && number <= end ) {
                                 ++count;
                                 break;
                         }
@@ -52,6 +52,33 @@ part1(const Ranges& ranges, const vector<long>& numbers)
         cout << "Part 1: " << count << '\n';
 }
 
+void
+part2(Ranges ranges)
+{
+        ranges::sort(ranges);
+
+        Ranges merged;
+        merged.emplace_back(ranges[0]);
+
+        for ( size_t i = 1; i < ranges.size(); ++i ) {
+                auto& [last_start, last_end] = merged.back();
+                auto& [curr_start, curr_end] = ranges[i];
+
+                if ( last_end < curr_start ) {
+                        merged.emplace_back(ranges[i]);
+                }
+                else if ( last_end < curr_end ) {
+                        last_end = curr_end;
+                }
+        }
+
+        long count = 0;
+        for ( const auto [start, end]: merged ) {
+                count += end - start + 1;
+        }
+        cout << "Part 2: " << count << '\n';
+}
+
 } // namespace
 
 int
@@ -59,4 +86,5 @@ main()
 {
         const auto [ranges, numbers] = read_file("data/day05.txt");
         part1(ranges, numbers);
+        part2(ranges);
 }