Finished task3 sem02-solutions-append

1 files changed, 262 insertions, 0 deletions

diff --git a/Sem. 02/task3.cpp b/Sem. 02/task3.cpp
new file mode 100644
index 0000000..67cebfc
--- /dev/null
+++ b/Sem. 02/task3.cpp
@@ -0,0 +1,262 @@
+#include <iostream>
+#include <fstream>
+#include <cstring> 
+#pragma warning(disable:4996)
+using namespace std;
+
+const size_t capacity = 1024;
+const size_t bufferCapacity = 2.5 * capacity; // rough estimation of size of "edit fn Specialty email", where fn, Specialty and email are with their max width
+
+enum class Speciality
+{
+	computerScience,
+	softwareEngineering
+};
+
+struct StudentRecord
+{
+	char firstName[capacity];
+	char lastName[capacity];
+
+	char fnRaw[capacity];
+
+	//parsed by fnRaw
+	Speciality studentSpeciality;
+	int fn;
+	//
+
+	char email[capacity];
+};
+
+struct StudentCollection
+{
+	StudentRecord* data;
+	size_t studentsCount;
+};
+
+size_t getLinesCount(const char* fileName)
+{
+	ifstream file(fileName);
+
+	if (!file.is_open())
+		return 0;
+
+	size_t count = 0;
+
+	while (!file.eof())
+	{
+		char buff[capacity];
+		file.getline(buff, capacity);
+		count++;
+	}
+
+	file.close();
+
+	return count;
+
+}
+
+void parseField(char* dest, const char*& source)
+{
+	while (*source != ',' && *source != '\0')
+	{
+		*dest = *source;
+		dest++;
+		source++;
+	}
+	source++;
+	*dest = '\0';
+}
+
+void parseFn(StudentRecord& currentStudent)
+{
+	if (strlen(currentStudent.fnRaw) < 5)
+		return;
+
+	if (currentStudent.fnRaw[4] == '6')
+		currentStudent.studentSpeciality = Speciality::softwareEngineering;
+	else if (currentStudent.fnRaw[4] == '8')
+		currentStudent.studentSpeciality = Speciality::computerScience;
+
+	currentStudent.fn = atoi(currentStudent.fnRaw + 5);
+
+}
+
+void parseStudent(StudentRecord& currentStudent, const char* line)
+{
+	parseField(currentStudent.firstName, line);
+	parseField(currentStudent.lastName, line);
+	parseField(currentStudent.fnRaw, line);
+	parseField(currentStudent.email, line);
+	parseFn(currentStudent);
+}
+
+void printStudent(const StudentRecord& st)
+{
+	std::cout << "First name: " << st.firstName << ", second name: " << st.lastName << ", speciality: ";
+
+	if (st.studentSpeciality == Speciality::computerScience)
+		std::cout << "computer science, ";
+	else
+		std::cout << "software engineering, ";
+
+	std::cout << "number: " << st.fn << ", email: " << st.email << std::endl;
+
+}
+
+void initStudentCollection(StudentCollection& collection, const char* fileName)
+{
+	size_t linesCount = getLinesCount(fileName);
+	
+	size_t studentsCount = linesCount - 1;
+	
+	ifstream file(fileName);
+	if (studentsCount == 0 || !file.is_open())
+	{
+		cout << "Error while reading from file!"  << std::endl;
+		collection.studentsCount = 0;
+		collection.data = nullptr;
+		
+		return;
+	}
+	
+	collection.data = new StudentRecord[studentsCount];
+	collection.studentsCount = studentsCount;
+
+	char buff[capacity];
+	file.getline(buff, capacity); ///skip the header
+	for (int i = 0; i < studentsCount; i++)
+	{
+		file.getline(buff, capacity);
+		parseStudent(collection.data[i], buff);
+	}
+}
+
+void saveToFile(const char* fileName, const StudentCollection& collection)
+{
+	ofstream file(fileName);
+	if (!file.is_open())
+		return;
+	file << "Ime, Familiya, Fakulteten nomer, Imeyl adres" << std::endl; //header;
+	for (int i = 0; i < collection.studentsCount; i++)
+	{
+	    file << collection.data[i].firstName << "," << collection.data[i].lastName << "," << collection.data[i].fnRaw << "," << collection.data[i].email;
+        
+        bool isLast = i == collection.studentsCount - 1;
+        
+        if(!isLast)
+            file << std::endl;
+	}
+	std::cout << "file " << fileName << " successfully saved!" << std::endl;
+}
+
+void accSubstr(const char*& raw, int& ind, char* output)
+{
+	for (int i = 0; raw[ind] != ' ' && raw[ind] != '\0'; i++, ind++)
+	{
+		output[i] = raw[ind];
+		output[i + 1] = '\0';
+	}
+	ind++;
+}
+
+int studentIndByFNAndSpeciality(const StudentCollection& collection, int fn, Speciality speciality) {
+	for (int i = 0; i < collection.studentsCount; i++)
+		if (collection.data[i].fn == fn && collection.data[i].studentSpeciality == speciality)
+			return i;
+
+	std::cout << "Error: No student found!" << std::endl;
+	return -1;
+}
+
+int studentIndByFNAndSpeciality(const StudentCollection& collection, const char* rawData, int& accInd)
+{
+	if (rawData[0] == ' ') accInd = 1;
+
+	char fnBuffer[capacity];
+	accSubstr(rawData, accInd, fnBuffer);
+
+	int fn = atoi(fnBuffer);
+	
+	char specBuffer[capacity];
+	accSubstr(rawData, accInd, specBuffer);
+
+	Speciality speciality;
+	if (strcmp(specBuffer, "SoftwareEngineering") == 0)
+		speciality = Speciality::softwareEngineering;
+	else if (strcmp(specBuffer, "ComputerScience") == 0)
+		speciality = Speciality::computerScience;
+
+	return studentIndByFNAndSpeciality(collection, fn, speciality);
+}
+
+int studentIndByFNAndSpeciality(const StudentCollection& collection, const char* rawData)
+{
+	int accInd = 0;
+	return studentIndByFNAndSpeciality(collection, rawData, accInd);
+}
+
+void printStudentInCollectionFromRaw(const StudentCollection& collection, const char* rawData)
+{
+	int studentInd = studentIndByFNAndSpeciality(collection, rawData);
+	if (studentInd < 0)
+		return;
+
+	printStudent(collection.data[studentInd]);
+}
+
+void editStudentEmailFromRaw(const StudentCollection& collection, const char* rawData)
+{
+	int accInd = 0, studentInd = studentIndByFNAndSpeciality(collection, rawData, accInd);
+	if (studentInd < 0)
+		return;
+
+	char emailBuffer[capacity];
+	accSubstr(rawData, accInd, emailBuffer);
+	strcpy(collection.data[studentInd].email, emailBuffer);
+}
+
+int main()
+{
+	std::cout << "Open file:" << std::endl;
+
+	char buffer[bufferCapacity];
+	std::cin.getline(buffer, bufferCapacity);
+
+	StudentCollection collection;
+	initStudentCollection(collection, buffer);
+	
+	if(collection.studentsCount == 0)
+	{
+	    std::cout << "Error! No students loaded!" << std::endl;
+	    return -1;
+	}
+	std::cout << "File successfully opened!" << std::endl;
+
+	do
+	{
+		std::cin >> buffer;
+		if (strcmp(buffer, "print") == 0)
+		{
+			std::cin.getline(buffer, bufferCapacity);
+			std::cout << buffer << std::endl;
+			printStudentInCollectionFromRaw(collection, buffer);
+		}
+		else if (strcmp(buffer, "edit") == 0)
+		{
+			std::cin.ignore();
+			std::cin.getline(buffer, bufferCapacity);
+			editStudentEmailFromRaw(collection, buffer);
+		}
+		else if (strcmp(buffer, "save") == 0)
+		{
+			std::cin >> buffer;
+			saveToFile(buffer, collection);
+			break;
+		}
+	} while(true);
+
+	delete[] collection.data;
+	
+	return 0;
+}