Add solution for 2016 Day 5

- Add Md5 algorithm to library

src/2016/Day05.cpp

@@ -2,30 +2,60 @@
 
 namespace y2016::day05
 {
-  REGISTER_DAY(2016, Day05, std::vector<int>, int);
+  REGISTER_DAY(2016, Day05, std::string, std::string);
 
-  REGISTER_TEST_EXAMPLE(2016, Day05, ExampleInput, 1, 0);
-  REGISTER_TEST(2016, Day05, Input, 1, 0);
-  REGISTER_TEST_EXAMPLE(2016, Day05, ExampleInput, 2, 0);
-  REGISTER_TEST(2016, Day05, Input, 2, 0);
+  REGISTER_TEST(2016, Day05, Input, 1, "f97c354d");
+  REGISTER_TEST(2016, Day05, Input, 2, "863dde27");
 
   READ_INPUT(input)
   {
-    std::vector<int> vec;
     std::string str;
-    while (getline(input, str))
-    {
-    }
-    return vec;
+    getline(input, str);
+    return str;
   }
 
   OUTPUT1(input)
   {
-    return 0;
+    int i = 0;
+    std::string result;
+    while (true)
+    {
+      std::string str = input + std::to_string(i);
+      std::string s = Md5::Hash(str);
+      if (Helper::StartsWith(s, "00000"))
+      {
+        result.push_back(s[5]);
+        if (result.size() == 8)
+          return result;
+      }
+      i++;
+    }
+    return "";
   }
 
   OUTPUT2(input)
   {
-    return 0;
+    int i = 0;
+    std::string result{"XXXXXXXX"};
+    int replacements = 0;
+    for (int i = 0;; i++)
+    {
+      std::string str = input + std::to_string(i);
+      std::string s = Md5::Hash(str);
+      if (Helper::StartsWith(s, "00000"))
+      {
+        if (s[5] < '0' || s[5] > '7')
+          continue;
+
+        if (result[s[5] - '0'] == 'X')
+        {
+          result[s[5] - '0'] = s[6];
+          replacements++;
+        }
+        if (replacements == 8)
+          return result;
+      }
+    }
+    return "";
   }
 }