[w2/ex3] Added solution

1 files changed, 135 insertions, 0 deletions

diff --git a/week02/Exercise3.cpp b/week02/Exercise3.cpp
new file mode 100644
index 0000000..4ea5332
--- /dev/null
+++ b/week02/Exercise3.cpp
@@ -0,0 +1,135 @@
+#include <iostream>
+#include <random>
+
+/* Решението изглежда странно, идеята на тази задача беше да се упражни употреба на указатели */
+
+int randBetween(int a, int b) {
+	return a + rand() % (b + 1);
+}
+
+int min(int a, int b) {
+	return (a > b) ? a : b;
+}
+
+struct Car {
+	int row;
+	int col;
+	int speed;
+
+	Car(int rows, int cols) {
+		row = randBetween(0, rows - 1);
+		col = randBetween(0, cols - 1);
+		speed = randBetween(4, 6);
+	}
+
+	int ForwardCol() {
+		return row + speed;
+	}
+
+	void MoveForward() {
+		col += speed;
+		if (speed == 0) {
+			speed = 1;
+		}
+		else if (speed < 8) {
+			speed = min(8, randBetween(0, 3));
+		}
+	}
+
+	bool TryCrash(Car& crashWith) {
+		if (ForwardCol() < crashWith.col) return false;
+
+		speed /= 2;
+		if (ForwardCol() < crashWith.col) return false;
+
+		crashWith.speed = speed = 0;
+		col = crashWith.col - 1;
+		return true;
+	}
+};
+
+struct Highway {
+private:
+	Car** cars; // Динамично-заделен масив от динамично-заделени коли
+	int carsSize;
+	int carsCount;
+
+	int rows;
+	int cols;
+
+	void initCars() {
+		for (int i = 0; i < carsSize; i++) {
+			cars[i] = new Car(rows, cols);
+		}
+		carsCount = carsSize;
+	}
+
+	Car** getCar(int row, int col) {
+		for (int i = 0; i < carsSize; i++) {
+			if (cars[i] != nullptr && cars[i]->row == row && cars[i]->col == col) {
+				return &cars[i];
+			}
+		}
+		return nullptr;
+	}
+
+	bool moveForward(Car& current, int row, int startCol, int endCol) {
+		for (int col = startCol + 1; col < endCol; col++) {
+			Car** collidesWith = getCar(row, col);
+			if (collidesWith != nullptr && current.TryCrash(**collidesWith)) {
+				return false;
+			}
+		}
+		current.MoveForward();
+		return true;
+	}
+
+public:
+	Highway(int rows, int cols, int size) {
+		this->rows = rows;
+		this->cols = cols;
+		this->carsSize = this->carsCount = size;
+		cars = new Car*[carsSize];
+	}
+	~Highway() {
+		for (int i = 0; i < carsSize; i++) {
+			delete cars[i];
+		}
+		delete[] cars;
+	}
+
+	int SimulateStep() {
+		int crashes = 0;
+		for (int j = cols - 1; j >= 0; j--) {
+			for (int i = 0; i < rows; i++) {
+				Car** current = getCar(i, j);
+				if (current == nullptr) continue;
+				crashes += !moveForward(**current, i, j, (*current)->ForwardCol());
+
+				if ((*current)->col >= cols) {
+					delete *current;
+					*current = nullptr;
+					carsCount--;
+				}
+			}
+		}
+		return crashes;
+	}
+
+	void Simulate() {
+		initCars();
+
+		int iterations = 1, crashes = 0;
+		while (carsCount > 0) {
+			crashes += SimulateStep();
+			iterations++;
+		}
+
+		std::cout << "Iters: " << iterations << " Crashes: " << crashes << std::endl;
+	}
+};
+
+int main() {
+	Highway h1(1, 10, 10);
+	h1.Simulate();
+}