D3 done

src/day-3-solution.cpp

@@ -0,0 +1,58 @@
+#include "spdlog/spdlog.h"
+#include <algorithm>
+#include <concepts>
+#include <fstream>
+#include <ranges>
+#include <string>
+#include <sys/types.h>
+#include <vector>
+
+uint_fast64_t get_joltage_part_one(std::string& line){
+  std::ranges::subrange<std::string::const_iterator, std::string::const_iterator> greedy_view
+  = std::ranges::subrange<std::string::const_iterator, std::string::const_iterator>{line.cbegin(),line.cend()-1};
+
+  std::string::const_iterator first_greedy_max = std::ranges::max_element(greedy_view);
+
+  std::ranges::subrange<std::string::const_iterator, std::string::const_iterator> greedy_view_second = std::ranges::subrange<std::string::const_iterator, std::string::const_iterator> {first_greedy_max+1, line.cend()};
+
+  std::string::const_iterator second_greedy_max = std::ranges::max_element(greedy_view_second);
+ 
+  return static_cast<uint_fast64_t>((*first_greedy_max - '0')*10 + (*second_greedy_max -'0'));
+}
+
+uint_fast64_t get_joltage_generalized(std::string& line, uint_fast64_t digits){
+  std::vector<std::string::const_iterator> digits_pointer_store = std::vector<std::string::const_iterator>{};
+  std::string::const_iterator offset = line.cbegin();
+  for (uint_fast64_t countdown = {digits}; countdown>0; countdown--) {
+      std::ranges::subrange<std::string::const_iterator, std::string::const_iterator> greedy_view
+  = std::ranges::subrange<std::string::const_iterator, std::string::const_iterator>{offset,line.cend()-countdown+1};
+    std::string::const_iterator digit_chosen  = std::ranges::max_element(greedy_view);
+    digits_pointer_store.push_back(digit_chosen);
+    offset = digit_chosen+1;
+  }
+  uint_fast64_t running_sum = uint_fast64_t {0};
+  
+  for (std::vector<std::string::const_iterator>::const_iterator i = digits_pointer_store.cbegin(); i!= digits_pointer_store.cend(); i++) { 
+    running_sum*=10;
+    running_sum+= static_cast<uint_fast64_t>(**i - '0');
+  }
+  return running_sum;
+}
+
+void solving_engine(std::ifstream& file) noexcept{
+  std::string current_line = std::string {};
+  uint_fast64_t running_joltage_sum_part_one = uint_fast64_t {0};
+  uint_fast64_t running_joltage_sum_part_two = uint_fast64_t {0};
+  while(std::getline(file, current_line)){
+    running_joltage_sum_part_one += get_joltage_part_one(current_line);
+    running_joltage_sum_part_two += get_joltage_generalized(current_line, 12);
+  }
+  spdlog::info("Part one Solution: {}", running_joltage_sum_part_one);
+  spdlog::info("Part two solution: {}", running_joltage_sum_part_two);
+}
+
+int main () {
+  std::ifstream input_file = std::ifstream {"testcases/day-3.in", std::ios_base::binary};
+  solving_engine(input_file);
+  return 0;
+}