Added part 2.

2022/9/main.cpp

@@ -6,13 +6,39 @@
 #include <unistd.h>
 #include <vector>
 
-void DebugPrint(std::pair<int, int> &head, std::pair<int, int> &tail,
-                std::set<std::pair<int, int> > &visited_positions)
+void ApplyMovement(std::pair<int, int> &head,
+                   std::pair<int, int> &tail)
 {
-	int x_min = head.first;
-	int y_min = head.second;
-	int x_max = head.first;
-	int y_max = head.second;
+	const int x_diff = head.first - tail.first;
+	const int y_diff = head.second - tail.second;
+	if(std::abs(x_diff) > 1) // 2 away
+	{
+		tail.first += (head.first - tail.first) / 2;
+		if(std::abs(y_diff) > 1) // 2 away due to diagonally following!!!
+			tail.second += (head.second - tail.second) / 2;
+		else
+			// snap to axis since you're already on it or you're one away
+			tail.second = head.second;
+	}
+	if(std::abs(y_diff) > 1) // 2 away
+	{
+		tail.second += (head.second - tail.second) / 2;
+		if(std::abs(x_diff) > 1) // 2 away due to diagonally following!!!
+			tail.first += (head.first - tail.first) / 2;
+		else
+			// snap to axis since you're already on it or you're one away
+			tail.first = head.first;
+	}
+}
+
+void DebugPrint(std::vector<std::pair<int, int> > &points,
+                std::set<std::pair<int, int> > &visited_positions,
+                std::set<std::pair<int, int> > &visited_positions_part2)
+{
+	int x_min = points[0].first;
+	int y_min = points[0].second;
+	int x_max = points[0].first;
+	int y_max = points[0].second;
 
 	for(auto &pos : visited_positions)
 	{
@@ -21,6 +47,13 @@ void DebugPrint(std::pair<int, int> &head, std::pair<int, int> &tail,
 		y_min = std::min(y_min, pos.second);
 		y_max = std::max(y_max, pos.second);
 	}
+	for(auto &pos : visited_positions_part2)
+	{
+		x_min = std::min(x_min, pos.first);
+		x_max = std::max(x_max, pos.first);
+		y_min = std::min(y_min, pos.second);
+		y_max = std::max(y_max, pos.second);
+	}
 
 	for(auto i = 0; i < 50; ++i)
 		std::cout << std::endl;
@@ -32,12 +65,30 @@ void DebugPrint(std::pair<int, int> &head, std::pair<int, int> &tail,
 	{
 		for(auto x = x_min; x <= x_max; ++x)
 		{
-			if(head.first == x && head.second == y)
+			if(points[0].first == x && points[0].second == y)
 				std::cout << "\033[1;30mH"; // head
-			else if(tail.first == x && tail.second == y)
-				std::cout << "\033[1;25mT"; // head
+			else if(points[1].first == x && points[1].second == y)
+				std::cout << "\033[1;25m1"; // tail
+			else if(points[2].first == x && points[2].second == y)
+				std::cout << "\033[1;25m2"; // tail
+			else if(points[3].first == x && points[3].second == y)
+				std::cout << "\033[1;25m3"; // tail
+			else if(points[4].first == x && points[4].second == y)
+				std::cout << "\033[1;25m4"; // tail
+			else if(points[5].first == x && points[5].second == y)
+				std::cout << "\033[1;25m5"; // tail
+			else if(points[6].first == x && points[6].second == y)
+				std::cout << "\033[1;25m6"; // tail
+			else if(points[7].first == x && points[7].second == y)
+				std::cout << "\033[1;25m7"; // tail
+			else if(points[8].first == x && points[8].second == y)
+				std::cout << "\033[1;25m8"; // tail
+			else if(points[9].first == x && points[9].second == y)
+				std::cout << "\033[1;25m9"; // tail
 			else if(visited_positions.contains({x, y}))
 				std::cout << "\033[1;31mX"; // red
+			else if(visited_positions_part2.contains({x, y}))
+				std::cout << "\033[1;20mY"; // ??
 			else
 				std::cout << "\033[0m-"; // default white
 		}
@@ -59,9 +110,11 @@ int main()
 	unsigned long total_pt2 = 0;
 
 	std::set<std::pair<int, int> > visited_positions;
+	std::set<std::pair<int, int> > visited_positions_part2;
 
-	std::pair<int, int> head = {0,0};
-	std::pair<int, int> tail = {0,0};
+	std::vector<std::pair<int, int> > points;
+	for(auto i = 0; i < 10; ++i)
+		points.push_back({0,0});
 
 	char dir;
 	int amt;
@@ -80,55 +133,34 @@ int main()
 			switch(dir)
 			{
 			case 'U':
-				head.second--;
+				points[0].second--;
 				break;
 			case 'D':
-				head.second++;
+				points[0].second++;
 				break;
 			case 'L':
-				head.first--;
+				points[0].first--;
 				break;
 			case 'R':
-				head.first++;
+				points[0].first++;
 				break;
 			}
 
 			// Follow with tail:
-			const int x_diff = head.first - tail.first;
-			const int y_diff = head.second - tail.second;
-			if(std::abs(x_diff) > 1) // 2 away
-			{
-				tail.first += (head.first - tail.first) / 2;
-				if(y_diff)
-				{
-					int to_change = std::ceil(std::abs(head.second - tail.second) / 2.0);
-					if(y_diff < 0)
-						tail.second -= to_change;
-					else
-						tail.second += to_change;
-				}
-			}
-			if(std::abs(y_diff) > 1) // 2 away
-			{
-				tail.second += (head.second - tail.second) / 2;
-				if(x_diff)
-				{
-					int to_change = std::ceil(std::abs(head.first - tail.first) / 2.0);
-					if(x_diff < 0)
-						tail.first -= to_change;
-					else
-						tail.first += to_change;
-				}
-			}
+			for(auto i = 0; i < points.size() - 1; ++i)
+				ApplyMovement(points[i], points[i+1]);
 
-			visited_positions.insert(tail);
-			// DebugPrint(head, tail, visited_positions);
-			// usleep(1000000);
+			visited_positions.insert(points[1]);
+			visited_positions_part2.insert(points.back());
+
+			DebugPrint(points, visited_positions, visited_positions_part2);
+			usleep(100000);
 		}
 	}
 
-	DebugPrint(head, tail, visited_positions);
+	DebugPrint(points, visited_positions, visited_positions_part2);
 	total = visited_positions.size();
+	total_pt2 = visited_positions_part2.size();
 
 	std::cout << "    Total: " <<     total << std::endl;
 	std::cout << "PT2 Total: " << total_pt2 << std::endl;