Day 1

.gitignore

@@ -1,3 +1,3 @@
 .DS_Store
 /build
-d*/.txt
+*.txt

CMakeLists.txt

@@ -11,7 +11,7 @@ set(CMAKE_CXX_COMPILER clang++)
 set(CMAKE_BUILD_TYPE Release)
 
 if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
-    set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -O3")
+    set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -O3 -Wno-c23-extensions")
 endif()
 
 set(executables d1 d2 d3 d4 d5 d6 d7 d8 d9 d10 d11 d12 d13 d14 d15 d16 d17 d18 d19 d20 d21 d22 d23 d24 d25)

d1/main.cxx

@@ -1,15 +1,56 @@
 #include <iostream>
-#include <fstream>
+#include <sstream>
+#include <vector>
+#include <unordered_map>
+#include <algorithm>
 
 using std::cout, std::endl;
 
-int main() {
+constexpr const char content[] = {
-    std::ifstream file{"../d1/input.txt"};
+    #embed "input.txt"
-    std::string line;
+};
 
-    while (std::getline(file, line)) {
+void part_1() {
+    std::vector<int> left_vec, right_vec;
+    std::istringstream iss{content}; 
 
+    int l_id, r_id;
+    while (iss >> l_id >> r_id) {
+        left_vec.emplace_back(l_id);
+        right_vec.emplace_back(r_id);
+    }
+    std::sort(left_vec.begin(), left_vec.end());
+    std::sort(right_vec.begin(), right_vec.end());
+
+    auto diff_acc{0};
+    for (auto i{0}; i < left_vec.size(); i++) {
+        diff_acc += std::abs(left_vec[i] - right_vec[i]);
     }
 
+    cout << diff_acc << endl;
+}
+
+void part_2() {
+    std::vector<int> left_vec;
+    std::unordered_map<int, int> right_map;
+    std::istringstream iss{content}; 
+
+    int l_id, r_id;
+    while (iss >> l_id >> r_id) {
+        left_vec.emplace_back(l_id);
+        right_map[r_id]++;
+    }
+
+    auto sim_acc{0};
+    for (auto left_num : left_vec) {
+        sim_acc += right_map[left_num] * left_num;
+    }
+
+    cout << sim_acc << endl;
+} 
+
+int main() {
+    part_1();
+    part_2();
     return 0;
 }