Bot class: first iteration, refactoring fix (Worm -> Snake)

include/Map.hpp

@@ -2,6 +2,7 @@
 
 #include <deque>
 #include <iostream>
+#include <optional>
 
 #include "Canvas.hpp"
 #include "Utils.hpp"
@@ -61,6 +62,21 @@ public:
     }
   }
 
+  std::optional<Veci> find_nearest_food(Veci pos) {
+    if (food_.empty()) {
+      return std::nullopt;
+    }
+
+    Veci target = food_.front().pos;
+    for (const auto &food : food_) {
+      if ((pos - food.pos).len_sq() < (pos - target).len_sq()) {
+        target = food.pos;
+      }
+    }
+
+    return target;
+  }
+
 private:
   void generate() {
     ++current_gen_;