5 files changed, 126 insertions, 0 deletions

diff --git a/2023/06/Makefile b/2023/06/Makefile
new file mode 100644
index 0000000..a3c2cea
--- /dev/null
+++ b/2023/06/Makefile
@@ -0,0 +1,18 @@
+CXXFLAGS := -std=c++17
+EXE := part1 part2
+
+.PHONY: all clean configure
+
+all: $(EXE)
+
+configure:
+        bear -- $(MAKE) all
+
+%.o: %.cpp
+        $(CXX) -c $(CXXFLAGS) $< -o $@
+
+clean:
+        rm -rf $(EXE) src/*.o compile_commands.json
+
+%: src/%.o
+        $(CXX) $^ -o $@
diff --git a/2023/06/resources/input.txt b/2023/06/resources/input.txt
new file mode 100644
index 0000000..e0996e8
--- /dev/null
+++ b/2023/06/resources/input.txt
@@ -0,0 +1,2 @@
+Time:        60     80     86     76
+Distance:   601   1163   1559   1300
diff --git a/2023/06/resources/input_small.txt b/2023/06/resources/input_small.txt
new file mode 100644
index 0000000..28f5ae9
--- /dev/null
+++ b/2023/06/resources/input_small.txt
@@ -0,0 +1,2 @@
+Time:      7  15   30
+Distance:  9  40  200
diff --git a/2023/06/src/part1.cpp b/2023/06/src/part1.cpp
new file mode 100644
index 0000000..2d50385
--- /dev/null
+++ b/2023/06/src/part1.cpp
@@ -0,0 +1,54 @@
+#include <iostream>
+#include <fstream>
+#include <sstream>
+#include <cstring>
+#include <vector>
+#include <cmath>
+
+int main(void)
+{
+    int answer{ 1 };
+    std::vector<int> time;
+    std::vector<int> distance;
+
+    std::ifstream input{ "resources/input.txt" };
+    if (input.is_open())
+    {
+        int n;
+        std::string line;
+
+        /* Time */
+        {
+            std::getline(input,line);
+            line.erase(0, std::strlen("Time:"));
+            std::istringstream sline{ line };
+            while(sline >> n)
+            {
+                time.push_back(n);
+            }
+        }
+
+        /* Distance */
+        {
+            std::getline(input,line);
+            line.erase(0, std::strlen("Distance:"));
+            std::istringstream sline{ line };
+            while(sline >> n)
+            {
+                distance.push_back(n);
+            }
+        }
+    }
+    input.close();
+
+    for (int i = 0; i < time.size(); ++i)
+    {
+        double delta = std::sqrt(time[i] * time[i] - 4 * distance[i]);
+        int from{ static_cast<int>(1 + (time[i] - delta) / 2)};
+        int to{ static_cast<int>(std::ceil((time[i] + delta) / 2)) };
+        answer *= to - from;
+    }
+
+    std::cout << answer << std::endl;
+    return 0;
+}
diff --git a/2023/06/src/part2.cpp b/2023/06/src/part2.cpp
new file mode 100644
index 0000000..db35b57
--- /dev/null
+++ b/2023/06/src/part2.cpp
@@ -0,0 +1,50 @@
+#include <iostream>
+#include <fstream>
+#include <sstream>
+#include <cstring>
+#include <vector>
+#include <cmath>
+
+int main(void)
+{
+    long time{};
+    long distance{};
+
+    std::ifstream input{ "resources/input.txt" };
+    if (input.is_open())
+    {
+        long n;
+        std::string line;
+
+        /* Time */
+        std::getline(input,line);
+        for(unsigned char c : line)
+        {
+            if (std::isdigit(c))
+            {
+                time *= 10;
+                time += c - '0';
+            }
+        }
+
+        /* Distance */
+        std::getline(input,line);
+        for(unsigned char c : line)
+        {
+            if (std::isdigit(c))
+            {
+                distance *= 10;
+                distance += c - '0';
+            }
+        }
+
+    }
+    input.close();
+
+    double delta = std::sqrt(time * time - 4 * distance);
+    long from{ static_cast<long>(1 + (time - delta) / 2)};
+    long to{ static_cast<long>(std::ceil((time + delta) / 2)) };
+
+    std::cout << to - from << std::endl;
+    return 0;
+}