Day 2

d2/main.cxx

@@ -0,0 +1,59 @@
+#include <iostream>
+#include <fstream>
+#include <sstream>
+#include <string>
+#include <vector>
+
+struct Game
+{
+  int nr;
+  int r;
+  int b;
+  int g;
+};
+
+constexpr unsigned int hash(const char *s, int off = 0)
+{
+  return !s[off] ? 5381 : (hash(s, off + 1) * 33) ^ s[off];
+}
+
+int main()
+{
+  constexpr int redCap{12}, blueCap{14}, greenCap{13};
+  std::ifstream file{"../d2/input.txt"};
+  std::string line, ignored, currentColor;
+  int sum{0}, currentNumber;
+
+  while (std::getline(file, line))
+  {
+    std::replace(line.begin(), line.end(), ':', ' ');
+    std::replace(line.begin(), line.end(), ';', ' ');
+    std::replace(line.begin(), line.end(), ',', ' ');
+
+    std::stringstream iss(line);
+    Game tempGame{};
+    iss >> ignored >> tempGame.nr;
+
+    while (iss.tellg() != -1)
+    {
+      iss >> currentNumber >> currentColor;
+
+      switch (hash(currentColor.c_str()))
+      {
+      case hash("red"):
+        tempGame.r = (currentNumber > tempGame.r) ? currentNumber : tempGame.r;
+        break;
+      case hash("green"):
+        tempGame.g = (currentNumber > tempGame.g) ? currentNumber : tempGame.g;
+        break;
+      case hash("blue"):
+        tempGame.b = (currentNumber > tempGame.b) ? currentNumber : tempGame.b;
+        break;
+      }
+    }
+    sum += tempGame.r * tempGame.b * tempGame.g;
+  }
+  std::cout << sum << std::endl;
+
+  return 0;
+}