5 files changed, 254 insertions, 0 deletions

diff --git a/week09/Exercise3/Train.cpp b/week09/Exercise3/Train.cpp
new file mode 100644
index 0000000..68d4206
--- /dev/null
+++ b/week09/Exercise3/Train.cpp
@@ -0,0 +1,132 @@
+#include "Train.h"
+#include <iostream>
+#include <cstring>
+#include <fstream>
+
+void Train::free() {
+	delete[] regionsFileName;
+	delete[] currentRegion;
+}
+
+void Train::copyFrom(const Train& other) {
+	strcpy(this->model, other.model);
+	this->railID = other.railID;
+	this->regionsFileName = new char[strlen(other.regionsFileName) + 1];
+	strcpy(this->regionsFileName, other.regionsFileName);
+	this->currentRegion = new char[strlen(other.currentRegion) + 1];
+	strcpy(this->currentRegion, other.currentRegion);
+}
+
+Train::Train() {
+	model[0] = '\0';
+	railID = 0;
+	regionsFileName = currentRegion = nullptr;
+}
+
+Train::~Train() {
+	free();
+}
+
+Train::Train(const Train& other) {
+	copyFrom(other);
+}
+
+Train& Train::operator=(const Train& other) {
+	if (this != &other) {
+		free();
+		copyFrom(other);
+	}
+	return *this;
+}
+
+Train::Train(Train&& other) {
+	strcpy(this->model, other.model);
+	this->railID = other.railID;
+
+	this->regionsFileName = other.regionsFileName;
+	other.regionsFileName = nullptr;
+	this->currentRegion = other.currentRegion;
+	other.currentRegion = nullptr;
+}
+
+void Train::setCurrentRegion(std::ifstream& inFile) {
+	int start = inFile.tellg();
+	while (!inFile.eof() && inFile.peek() != '\n') {
+		inFile.get();
+	}
+	inFile.clear();
+
+	int length = inFile.tellg();
+	this->currentRegion = new char[length + 1];
+
+	inFile.seekg(start, std::ios::beg);
+	inFile.getline(this->currentRegion, length + 1);
+}
+
+Train::Train(const char model[128], unsigned railID, const char* regionsFileName) {
+	strcpy(this->model, model);
+	this->railID = railID;
+	this->regionsFileName = new char[strlen(regionsFileName) + 1];
+	strcpy(this->regionsFileName, regionsFileName);
+
+	std::ifstream inFile(regionsFileName);
+	if (!inFile.is_open()) {
+		throw "Couldn't open regions file!";
+	}
+
+	setCurrentRegion(inFile);
+
+	inFile.close();
+}
+
+// Обикаля сегашния ред във файла и сравнява всяка буква със съответната от str
+// Във всички случаи предвижва inFile напред към следващия ред
+bool fileStringEq(std::ifstream& inFile, const char* str) {
+	if (inFile.eof()) {
+		inFile.close();
+		throw -1;
+	}
+
+	bool equal = true;
+	while (!inFile.eof() && inFile.peek() != '\n') {
+		if (inFile.peek() != *str) {
+			equal = false;
+		}
+		inFile.get();
+		if (*str != '\0') str++;
+	}
+
+	if (!inFile.eof()) {
+		inFile.get();
+	}
+	return equal && *str == '\0';
+}
+
+void Train::TransferNextRegion() {
+	std::ifstream inFile(regionsFileName);
+	if (!inFile.is_open()) {
+		throw "Couldn't open regions file!";
+	}
+
+	while (!fileStringEq(inFile, currentRegion));
+	setCurrentRegion(inFile);
+
+	inFile.close();
+}
+
+void Train::SwitchRailLine(unsigned railID, const char* regionsFileName) {
+	this->railID = railID;
+	delete[] this->regionsFileName;
+
+	this->regionsFileName = new char[strlen(regionsFileName) + 1];
+	strcpy(this->regionsFileName, regionsFileName);
+
+	std::ifstream inFile(regionsFileName);
+	if (!inFile.is_open()) {
+		throw "Couldn't open regions file!";
+	}
+
+	setCurrentRegion(inFile);
+
+	inFile.close();
+}
diff --git a/week09/Exercise3/Train.h b/week09/Exercise3/Train.h
new file mode 100644
index 0000000..6b90477
--- /dev/null
+++ b/week09/Exercise3/Train.h
@@ -0,0 +1,29 @@
+#pragma once
+#include <iostream>
+
+class Train {
+	char model[128];
+	unsigned railID;
+	char* regionsFileName;
+	char* currentRegion;
+
+	void free();
+	void copyFrom(const Train& other);
+
+	void setCurrentRegion(std::ifstream& inFile);
+
+public:
+	Train();
+	~Train();
+	Train(const Train& other);
+	Train& operator=(const Train& other);
+	Train(Train&& other);
+	Train& operator=(Train&& other);
+
+	Train(const char model[127], unsigned railID, const char* regionsFileName);
+
+	void TransferNextRegion();
+	void SwitchRailLine(unsigned railID, const char* regionsFileName);
+
+	friend class TrainNetwork;
+};
diff --git a/week09/Exercise3/TrainNetwork.cpp b/week09/Exercise3/TrainNetwork.cpp
new file mode 100644
index 0000000..cf9b6a9
--- /dev/null
+++ b/week09/Exercise3/TrainNetwork.cpp
@@ -0,0 +1,73 @@
+#include "TrainNetwork.h"
+#include <cstring>
+#include <fstream>
+
+bool TrainNetwork::HaveCollided(int index1, int index2) {
+	if (trains[index1].railID != trains[index2].railID) {
+		return false;
+	}
+	if (strcmp(trains[index1].currentRegion, trains[index2].currentRegion) != 0) {
+		return false;
+	}
+
+	std::ifstream regionFile(trains[index1].regionsFileName);
+	if (!regionFile.is_open()) {
+		throw "Couldn't open region file!";
+	}
+
+	// Обикаляме файла от края към началото и сравняваме всяка буква със съответната от сегашния регион
+	// Тоест сравняваме последния ред във файла със сегашния
+	regionFile.seekg(-1, std::ios::end); // Често текстови редактори слагат едно \n в края на файла, затова го пропускаме
+	                                     // Това и да го направите и да не го е все едно
+	int regionIndex = strlen(trains[index1].currentRegion) - 1;
+	while (!regionFile.fail() && regionFile.peek() != '\n' && regionIndex >= 0) {
+		// Щом последния ред (последната локация) се различава от сегашната, то
+		// сегашната ще се намира някъде другаде във файла и ще има колизия
+		if (regionFile.peek() != trains[index1].currentRegion[regionIndex]) {
+			regionFile.close();
+			return true;
+		}
+		regionIndex--;
+		regionFile.seekg(-1, std::ios::cur);
+	}
+
+	bool lastLineEqualsCurrent = (regionFile.tellg() == -1 || regionFile.peek() == '\n') && regionIndex == 0;
+	regionFile.close();
+
+	return !lastLineEqualsCurrent;
+}
+
+int TrainNetwork::RunTrains() {
+	bool anyMovedForward = true;
+	while (anyMovedForward) {
+		anyMovedForward = false;
+
+		for (int i = 0; i < 512; i++) {
+			if (collided[i]) continue;
+
+			for (int j = 0; j < 512; j++) {
+				if (collided[j] || j == i) continue;
+
+				if (HaveCollided(i, j)) {
+					collided[i] = collided[j] = true;
+					break;
+				}
+			}
+
+			if (collided[i]) continue;
+
+			try {
+				trains[i].TransferNextRegion();
+				anyMovedForward = true;
+			}
+			catch (int error) {
+			}
+		}
+	}
+
+	int sum = 0;
+	for (int i = 0; i < 512; i++) {
+		sum += collided[i];
+	}
+	return sum;
+}
diff --git a/week09/Exercise3/TrainNetwork.h b/week09/Exercise3/TrainNetwork.h
new file mode 100644
index 0000000..2d40879
--- /dev/null
+++ b/week09/Exercise3/TrainNetwork.h
@@ -0,0 +1,12 @@
+#pragma once
+#include "Train.h"
+
+class TrainNetwork {
+	char id[8];
+	Train trains[512];
+	bool collided[512];
+
+public:
+	bool HaveCollided(int index1, int index2);
+	int RunTrains();
+};
diff --git a/week09/Exercise3/main.cpp b/week09/Exercise3/main.cpp
new file mode 100644
index 0000000..d9ebd6f
--- /dev/null
+++ b/week09/Exercise3/main.cpp
@@ -0,0 +1,8 @@
+#include "Train.h"
+
+int main() {
+	Train t("abc", 1, "train.txt");
+	t.TransferNextRegion();
+	t.TransferNextRegion();
+	t.TransferNextRegion();
+}