Day 3

d3/main.cxx

@@ -0,0 +1,51 @@
+#include <iostream>
+#include <fstream>
+#include <sstream>
+#include <string>
+#include <cctype>
+#include <vector>
+
+uint32_t getPrio(std::string &fst, std::string &snd, std::string &thd)
+{
+  for (auto &i1 : fst)
+    for (auto &i2 : snd)
+      for (auto &i3 : thd)
+        if (i1 == i2 && i2 == i3)
+        {
+          if (std::isupper(i1))
+          {
+            return 27 + (i1 % 65);
+          }
+          else
+          {
+            return 1 + (i1 % 97);
+          }
+        }
+
+  return 0;
+}
+
+int main()
+{
+  std::ifstream file{"../d3/input.txt"};
+  std::vector<std::string> input;
+  std::string line;
+  while (std::getline(file, line))
+    input.push_back(line);
+
+  uint32_t sum{0};
+  std::string fst{""}, snd{""}, thd{""};
+
+  for (int i{2}; i < input.size(); i += 3)
+  {
+    fst = input[i - 2];
+    snd = input[i - 1];
+    thd = input[i];
+
+    sum += getPrio(fst, snd, thd);
+  }
+
+  std::cout << sum << std::endl;
+
+  return 0;
+}