From 109a964cb521ddd9e5212e5be02ed046240866b2 Mon Sep 17 00:00:00 2001
From: Mars Ultor <krishna@ayyalasomayajula.net>
Date: Sat, 6 Dec 2025 14:10:31 -0600
Subject: [PATCH] done with day 6 part 1

---
 src/day-6-solution.cpp | 81 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)
 create mode 100644 src/day-6-solution.cpp

diff --git a/src/day-6-solution.cpp b/src/day-6-solution.cpp
new file mode 100644
index 0000000..ef34c2e
--- /dev/null
+++ b/src/day-6-solution.cpp
@@ -0,0 +1,81 @@
+#include "spdlog/spdlog.h"
+#include <algorithm>
+#include <charconv>
+#include <cstdint>
+#include <cstdio>
+#include <fstream>
+#include <ios>
+#include <ranges>
+#include <string>
+#include <string_view>
+#include <utility>
+#include <vector>
+
+enum class Operation {
+  ADD='+', MULTIPLY='*'
+};
+
+
+uint_fast64_t part_one_solve_worksheet(const std::vector<std::pair<std::vector<uint_fast64_t>, Operation>>& worksheet){
+  uint_fast64_t running_sum = uint_fast64_t {0};
+  for (std::vector<std::pair<std::vector<uint_fast64_t>,Operation>>::const_iterator i  = worksheet.cbegin(); i<worksheet.cend(); i++) {
+    uint_fast64_t current_calc = * i->first.begin();
+    switch (i->second) {
+      case Operation::ADD :
+        for (std::vector<uint_fast64_t>::const_iterator j = i->first.cbegin()+1; j< i->first.cend(); j++) {
+          current_calc+= *j; 
+        }
+        break;
+      case Operation::MULTIPLY:
+        for (std::vector<uint_fast64_t>::const_iterator j = i->first.cbegin()+1; j< i->first.cend() ; j++) {
+          current_calc*= *j; 
+        }
+    }
+    running_sum+=current_calc;
+  }
+  return running_sum;
+}
+std::vector<std::pair<std::vector<uint_fast64_t>, Operation>> part_one_parse(std::ifstream& input_file){
+  
+  std::vector<std::pair<std::vector<uint_fast64_t>, Operation>> worksheet = std::vector<std::pair<std::vector<uint_fast64_t>, Operation>> {};
+  std::string current_line = std::string{};
+  while (std::getline(input_file, current_line)) {
+    
+std::string_view current_line_string_view = std::string_view{current_line};
+    auto split_view = std::ranges::views::split(current_line_string_view, ' ');
+    
+    std::vector<std::string_view> groups = std::vector<std::string_view>{};
+    for (auto&& token : split_view) {
+      if(token.empty()) continue;
+      groups.push_back(std::string_view{token});
+    }
+
+    if(worksheet.empty()) worksheet.assign(groups.size(), std::pair<std::vector<uint_fast64_t>, Operation> { std::vector<uint_fast64_t> {}, Operation::ADD });
+
+    if(input_file.peek()==EOF){
+        
+      for (std::vector<std::string_view>::const_iterator i = groups.begin(); i<groups.end(); i++) {
+        worksheet[static_cast<size_t>(i-groups.begin())].second = static_cast<Operation>(*(i->begin()));
+      }
+
+    }else{
+      for (std::vector<std::string_view>::const_iterator i = groups.begin(); i<groups.end(); i++) {
+        uint_fast64_t value; 
+        std::from_chars(i->data(), i->data() + i->size(), value);
+        worksheet[static_cast<size_t>(i-groups.begin())].first.push_back(value);
+      }
+    }
+  }
+  input_file.seekg(0);
+  return worksheet;
+}
+
+
+int main (int argc, char *argv[]) {
+  std::ifstream input_file = std::ifstream{"testcases/day-6.in"};
+  std::vector<std::pair<std::vector<uint_fast64_t>, Operation>> part_one_worksheet = part_one_parse(input_file);
+  spdlog::info("Number of problems captured: {}", part_one_worksheet.size());
+  uint_fast64_t part_one_result = part_one_solve_worksheet(part_one_worksheet);
+  spdlog::info("Part one solution: {}", part_one_result);
+  return 0;
+}