day2 part one done

day2/day.cpp

@@ -25,9 +25,6 @@ int main() {
 
   int res = 0;
   if (inputfile.is_open()) {
-
-    // Read each line from the file and store it in the
-    // 'line' variable.
     std::string line;
     std::vector<std::string> num_s;
     std::vector<int> num;
@@ -35,56 +32,49 @@ int main() {
     while (std::getline(inputfile, line)) {
       num_s = splitString(line);
       num.clear();
+
+      // Convert strings to integers
       std::transform(num_s.begin(), num_s.end(), std::back_inserter(num),
                      [](const std::string &s) { return std::stoi(s); });
+
+      // decreasing
       bool safe = true;
-      int old_n = -1;
-      for (int n : num) {
-        if (old_n == -1) {
-          old_n = n;
-          continue;
-        }
-        if ((old_n - n) > 2 || (old_n - n) < 0 || old_n == n) {
+      for (size_t i = 1; i < num.size(); ++i) {
+        int diff = num[i - 1] - num[i];
+        if (diff < 1 || diff > 3) {
           safe = false;
           break;
         }
-        old_n = n;
       }
+
       if (safe) {
         res++;
-        std::cerr << line << "\n";
+        std::clog << line << std::endl;
         continue;
       }
+
+      // increasing
       safe = true;
-      old_n = -1;
-      for (int n : num) {
-        if (old_n == -1) {
-          old_n = n;
-          continue;
-        }
-        if ((n - old_n) > 3 || (n - old_n) < 0 || old_n == n) {
+      for (size_t i = 1; i < num.size(); ++i) {
+        int diff = num[i] - num[i - 1];
+        if (diff < 1 || diff > 3) {
           safe = false;
           break;
         }
-        old_n = n;
       }
+
       if (safe) {
-        std::cerr << line << "\n";
+        std::clog << line << std::endl;
         res++;
       }
     }
 
-    // Close the file stream once all lines have been
-    // read.
     inputfile.close();
   } else {
-    // Print an error message to the standard error
-    // stream if the file cannot be opened.
     std::cerr << "Unable to open file!" << std::endl;
     return ENOENT;
   }
 
-  std::cout << "\n\n" << res << "\n\n";
-
+  std::cout << res << std::endl;
   return 0;
-}
+}