2 files changed, 60 insertions, 1 deletions

diff --git a/2015/src/day01.cpp b/2015/src/day01.cpp
new file mode 100644
index 0000000..5d6d482
--- /dev/null
+++ b/2015/src/day01.cpp
@@ -0,0 +1,54 @@
+#include <fstream>
+#include <iostream>
+#include <string>
+
+using namespace std;
+
+string
+read_file(string_view filename)
+{
+        fstream input{ filename };
+        return { istreambuf_iterator<char>{ input }, {} };
+}
+
+void
+part1(string_view puzzle)
+{
+        int floor = 0;
+        for (const auto& chr : puzzle) {
+                if (chr == '(') {
+                        ++floor;
+                }
+                else if (chr == ')') {
+                        --floor;
+                }
+        }
+        cout << floor << endl;
+}
+
+void
+part2(string_view puzzle)
+{
+        int floor = 0;
+        for (string_view::size_type pos = 0; pos != puzzle.length(); ++pos) {
+                const auto chr = puzzle[pos];
+                if (chr == '(') {
+                        ++floor;
+                }
+                else if (chr == ')') {
+                        --floor;
+                }
+                if (floor == -1) {
+                        cout << pos+1 << endl;
+                        break;
+                }
+        }
+}
+
+int
+main()
+{
+        auto puzzle = read_file("data/day01.txt");
+        part1(puzzle);
+        part2(puzzle);
+}
diff --git a/makefile b/makefile
index 494ced4..d88478f 100644
--- a/makefile
+++ b/makefile
@@ -1,12 +1,17 @@
 include config.mk
 
-all: $(patsubst 2020/src/%.cpp,2020/bin/%,$(wildcard 2020/src/*.cpp)) \
+all: $(patsubst 2015/src/%.cpp,2015/bin/%,$(wildcard 2015/src/*.cpp)) \
+        $(patsubst 2020/src/%.cpp,2020/bin/%,$(wildcard 2020/src/*.cpp)) \
         $(patsubst 2022/src/%.cpp,2022/bin/%,$(wildcard 2022/src/*.cpp)) \
         $(patsubst 2023/src/%.cpp,2023/bin/%,$(wildcard 2023/src/*.cpp))
 
 %/bin:
         mkdir -p $@
 
+# 2015
+2015/bin/%: 2015/src/%.cpp | 2015/bin
+        c++ $(CPPFLAGS) $^ -o $@
+
 # 2020
 2020/bin/%: 2020/src/%.cpp | 2020/bin
         c++ $(CPPFLAGS) $^ -o $@