feat: complete AoC 2020-12-06

day_6/.gitignore

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+/.idea
+/cmake-build-debug
+sample.txt

day_6/CMakeLists.txt

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+cmake_minimum_required(VERSION 3.19)
+project(day_6)
+
+set(CMAKE_CXX_STANDARD 20)
+
+add_executable(day_6 main.cpp)

day_6/main.cpp

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+#include <iostream>
+#include <fstream>
+#include <unordered_map>
+#include <variant>
+
+
+void part1(std::ifstream &input) {
+    uint32_t count = 0;
+    std::string groupAnswers;
+    std::string line;
+
+    groupAnswers = "";
+
+    while(std::getline(input, line)) {
+        if (line.empty()) {
+            count += groupAnswers.length();
+            groupAnswers = "";
+            continue;
+        }
+
+        for (char c : line) {
+            if (groupAnswers.find_first_of(c) == std::variant_npos) {
+                groupAnswers += c;
+            }
+        }
+    }
+
+    // Account for last entry
+    count += groupAnswers.length();
+
+    std::cout << "[P1] Count: " << count << std::endl;
+}
+
+void part2(std::ifstream &input) {
+    std::unordered_map<char, uint32_t> map = {};
+    uint32_t count = 0;
+    uint32_t memberCount = 0;
+    std::string line;
+
+    while (std::getline(input, line)) {
+        if (line.empty()) {
+            for (std::pair<const char, uint32_t> record : map) {
+                if (record.second == memberCount) count++;
+            }
+
+            memberCount = 0;
+            map = {};
+            continue;
+        }
+
+        for (char c : line) {
+            uint32_t value = 0;
+            if (map.contains(c)) value = map.at(c);
+            map.insert_or_assign(c, value + 1);
+        }
+
+        memberCount++;
+    }
+
+    // Check for one missing?
+    for (std::pair<const char, uint32_t> record : map) {
+        if (record.second == memberCount) count++;
+    }
+
+    std::cout << "[P2] Count: " << count << std::endl;
+}
+
+
+
+int main() {
+    std::ifstream input { "../input.txt" };
+
+    part1(input);
+    input.clear();
+    input.seekg(0);
+    part2(input);
+    return 0;
+}