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clean up
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| -rw-r--r-- | Sem. 04/README.md | 238 | ||||
| -rw-r--r-- | Sem. 04/task1/uni-task.cpp | 378 |
diff --git a/Sem. 04/README.md b/Sem. 04/README.md deleted file mode 100644 index 8974ae7..0000000 --- a/Sem. 04/README.md +++ /dev/null @@ -1,238 +0,0 @@ -
-
-
-# Структури и двоични файлове.
-### Размер на структура:
- ```c++
-#include <iostream>
-using namespace std;
-
-struct A
-{
- int a;
- int b;
-};
-
-int main()
-{
- cout << sizeof(A) << endl; // 8 bytes (4 bytes for each int)
-
- return 0;
-}
- ```
-
- Ето как изглежда структурата в паметта:
-
-
- 
-
-Пример за **естествено подравняване**:
-
- ```c++
-#include <iostream>
-
-using namespace std;
-
-struct B
-{
- char ch;
- int a;
-};
-
-int main()
-{
- cout << sizeof(B); // 8 byte-s
-
- return 0;
-}
-
- ```
- В паметта нещата изглеждат така:
-
-
-
-### Подравняване
-При представянето на обект (от някакъв тип) в паметта:
-
-- В паметта променливите са разположени **в същия ред**, в който са декларирани в структурата.
- - Подравняването става по **големината на най-голямата примитивна член-променлива** на структурата - размерът на структурата трябва да се дели на размерът на най-голямата променлива.
- - *Неформално*: Всяка променлива трябва да е на байт (ако приемем, че байтовете имат индекс, започвайки от 0), който е **кратен на големината на променливата**.
-
- За постигане на най-компактно представяне полетата на структурата да се сортират по тяхната големина в низходящ ред
-
-### Пример за записване на обекти във файл.
- ```c++
-#include <iostream>
-#include <fstream>
-using namespace std;
-
-struct Test
-{
- char ch;
- int a;
-};
-int main()
-{
- ofstream f("output.dat", ios::binary);
-
- if(!f.is_open())
- {
- cout << "Error!" << endl;
- return -1;
- }
-
- Test arr[3] = {{'a', 400},{'b', 500},{'c', 600}};
-
- f.write((const char*)&arr, sizeof(arr));
-
- f.close();
-
- return 0;
-}
-
- ```
-
-След изпълнението на програмата, файлът (**output.dat**) изглежда така:
-
-
-
-
-
-
-
-### Пример за записване на обекти, които съдържат динамично заделени данни, във файл.
- ```c++
-#include <iostream>
-#include <fstream>
-
-using namespace std;
-
-
-struct Student
-{
- char* name;
- int fn;
- int gradesCount;
- double averageGrade;
-};
-void print(const Student& st)
-{
- cout << st.name << " " << st.fn << " " << st.gradesCount << " " << st.averageGrade << endl;
-}
-Student createStudent(const char* name, int fn, int gradesCount, double avGrade)
-{
- Student obj;
-
- size_t nameLen = strlen(name);
-
- obj.name = new char[nameLen + 1];
- strcpy(obj.name, name);
-
- obj.fn = fn;
- obj.gradesCount = gradesCount;
- obj.averageGrade = avGrade;
-
- return obj;
-}
-void saveStudentToFile(ofstream& f, const Student& st)
-{
- size_t nameLen = strlen(st.name);
-
- f.write((const char*)&nameLen, sizeof(nameLen)); //first we write the size of the name!
- f.write(st.name, nameLen);
-
- f.write((const char*)&st.fn, sizeof(st.fn));
- f.write((const char*)&st.gradesCount, sizeof(st.gradesCount));
- f.write((const char*)&st.averageGrade, sizeof(st.averageGrade));
-
-}
-Student readStudentFromFile(ifstream& f)
-{
- Student res;
-
- size_t nameLen;
-
- f.read((char *)&nameLen, sizeof(nameLen)); //first we read the size of the name!
-
- res.name = new char[nameLen + 1];
- f.read(res.name, nameLen);
- res.name[nameLen] = '\0';
-
- f.read((char *)&res.fn, sizeof(res.fn));
- f.read((char*)&res.gradesCount, sizeof(res.gradesCount));
- f.read((char*)&res.averageGrade, sizeof(res.averageGrade));
-
- return res;
-}
-void freeStudent(Student& s)
-{
- delete[] s.name;
-
- s.averageGrade = s.fn = s.gradesCount = 0;
-
-}
-
-
-int main()
-{
- { //save students to file
- Student s1 = createStudent("Ivan", 1234, 2, 4);
- Student s2 = createStudent("Petur", 5555, 5, 5.5);
-
- ofstream f1("uni.dat", ios::binary);
-
- if (!f1.is_open())
- {
- cout << "Error" << endl;
- return -1;
- }
-
- saveStudentToFile(f1, s1);
- saveStudentToFile(f1, s2);
-
- freeStudent(s1);
- freeStudent(s2);
-
- f1.close();
- }
-
- { //read students from file
- ifstream f2("uni.dat", ios::binary);
-
- if (!f2.is_open())
- {
- cout << "Error" << endl;
- return -1;
- }
- Student s1 = readStudentFromFile(f2);
- Student s2 = readStudentFromFile(f2);
-
- print(s1);
- print(s2);
-
- freeStudent(s1);
- freeStudent(s2);
-
- f2.close();
- }
-}
-
-
- ```
-
-### Задачи
-
-**Задача 1:** Да се реализира система за база данни **произволен брой унивеситети**. Всеки университет има име (**низ до 32 символа**) и колекция от студенти (**произволен брой**). Всеки студент има - име (**низ с произволна дължина**), факултетен номер, брой получени оценки и средна оценка. Релизирайте **записване във файл и четене от файл** за базата данни. Релизирайте и следнита функции:
-
-- По подадено име на университет и факултетен номер на студент променя името на студента.
-
-*changeName(const char * uni, int fn, const char * newName)*
-
-- Добавяне на оценка на даден студент. След добавянето на оценката, трябва да се обнови броят получени оценки и средната оценка.
-
- *addGrade(const char * uni, int fn, int grade)*
-
-- Функция, която сортира университите по среден успех на студентите.
-
-*sort(uni *, size_t unisCount)*
-
diff --git a/Sem. 04/task1/uni-task.cpp b/Sem. 04/task1/uni-task.cpp deleted file mode 100644 index 0b534c0..0000000 --- a/Sem. 04/task1/uni-task.cpp +++ /dev/null @@ -1,378 +0,0 @@ -#include <iostream>
-#include<cstring>
-#include<fstream>
-#pragma warning(disable : 4996)
-
-struct Student
-{
- char* name;
- int fn;
- int gradesCount;
- double averageGrade;
-};
-
-struct University
-{
- char name[32];
- Student* collection;
- size_t studentsCount;
-};
-
-void print(const Student& st)
-{
- std::cout << std::endl << "======STUDENT======" << std::endl;
- std::cout << "Name: " << st.name << std::endl << "Faculcy number:" << st.fn <<
- std::endl << "Grades: " << st.gradesCount << std::endl << "Avarage: " << st.averageGrade << std::endl;
-}
-
-Student createStudent(const char* name, int fn, int gradesCount, double avGrade)
-{
- Student obj;
-
- size_t nameLen = strlen(name);
-
- obj.name = new char[nameLen + 1];
- strcpy(obj.name, name);
-
- obj.fn = fn;
- obj.gradesCount = gradesCount;
- obj.averageGrade = avGrade;
-
- return obj;
-}
-
-void freeStudent(Student& s)
-{
- delete[] s.name;
-
- s.averageGrade = s.fn = s.gradesCount = 0;
-
-}
-
-void saveStudentToFile(std::ofstream& f, const Student& st)
-{
- size_t nameLen = strlen(st.name);
-
- f.write((const char*)&nameLen, sizeof(nameLen)); //first we write the size of the name!
- f.write(st.name, nameLen);
-
- f.write((const char*)&st.fn, sizeof(st.fn));
- f.write((const char*)&st.gradesCount, sizeof(st.gradesCount));
- f.write((const char*)&st.averageGrade, sizeof(st.averageGrade));
-}
-
-Student readStudentFromFile(std::ifstream& f)
-{
- Student res;
-
- size_t nameLen;
-
- f.read((char*)&nameLen, sizeof(nameLen)); //first we read the size of the name!
-
- res.name = new char[nameLen + 1];
- f.read(res.name, nameLen);
- res.name[nameLen] = '\0';
-
- f.read((char*)&res.fn, sizeof(res.fn));
- f.read((char*)&res.gradesCount, sizeof(res.gradesCount));
- f.read((char*)&res.averageGrade, sizeof(res.averageGrade));
-
- return res;
-}
-
-University createUniversity(const char* _name, const Student* collection, const size_t& studentCount)
-{
- University uni;
-
- strcpy(uni.name, _name);
- uni.collection = new Student[studentCount];
- uni.studentsCount = studentCount;
-
- for (size_t i = 0; i < studentCount; i++)
- {
- uni.collection[i] = collection[i];
- }
-
- return uni;
-}
-
-void saveUniversityToFile(std::ofstream& outStream, const University& Uni)
-{
- //Writing the name of the university first:
- outStream.write(Uni.name, 32);
-
- //Then we write the students count:
- outStream.write((const char*)(&Uni.studentsCount), sizeof(Uni.studentsCount));
-
- //Writing every single student:
- size_t count = Uni.studentsCount;
- for (size_t i = 0; i < count; i++)
- {
- saveStudentToFile(outStream, Uni.collection[i]);
- }
-}
-
-University readUniFromFile(std::ifstream& inFile)
-{
- //to return:
- University uni;
-
- //We follow the same read order as we wrote them:
-
- //name:
- inFile.read((char*)(&uni.name), 32);
-
- //count:
- inFile.read((char*)(&uni.studentsCount), sizeof(uni.studentsCount));
-
- //students:
- size_t studentsCount = uni.studentsCount;
- uni.collection = new Student[studentsCount];
-
- for (size_t i = 0; i < studentsCount; i++)
- {
- uni.collection[i] = readStudentFromFile(inFile);
- }
-
- return uni;
-}
-
-void printUni(const University& uni)
-{
- size_t studentsCount = uni.studentsCount;
-
- std::cout << std::endl << "----------" << uni.name << "----------";
-
- for (size_t i = 0; i < studentsCount; i++)
- {
- print(uni.collection[i]);
- std::cout << std::endl;
- }
- std::cout << "-------------------------";
-}
-
-void freeUni(University& uni)
-{
- for (int i = 0; i < uni.studentsCount; i++)
- freeStudent(uni.collection[i]);
-
- strcpy(uni.name, "");
- uni.studentsCount = 0;
-}
-
-void changeStudentName(Student& st, const char* newName)
-{
- delete[] st.name;
- st.name = new char[strlen(newName) + 1];
- strcpy(st.name, newName);
-}
-
-void changeName(University* uniCollection, const int& uniCount, const char* uni, const int& fn, const char* newName)
-{
- int uniFound = -1;
- int studentFound = -1;
-
- for (int i = 0; i < uniCount; i++)
- {
- if (strcmp(uniCollection[i].name, uni) != 0)
- {
- continue;
- }
-
-
- uniFound = i;
- size_t studentsCount = uniCollection[i].studentsCount;
-
- for (size_t j = 0; j < studentsCount; j++)
- {
- if (uniCollection[i].collection[j].fn != fn)
- {
- continue;
- }
-
- studentFound = j;
- changeStudentName(uniCollection[i].collection[j], newName);
- break;
- }
- break;
- }
-
- if (uniFound != -1 && studentFound != -1)
- {
- std::cout << std::endl << "Changed: " << std::endl;
- print(uniCollection[uniFound].collection[studentFound]);
- }
- else
- {
- std::cout << std::endl << "No such student in this university" << std::endl;
- }
-}
-
-void addStudentGrade(Student& st, const int& grade)
-{
- double newAvarageGrade = (double)((st.averageGrade * st.gradesCount) + grade) / (double)(st.gradesCount + 1);
- st.averageGrade = newAvarageGrade;
- st.gradesCount++;
-}
-
-void addGrade(University* uniCollection, const int& uniCount, const char* uni, const int& fn, const int& grade)
-{
- int uniFound = -1;
- int studentFound = -1;
-
- for (int i = 0; i < uniCount; i++)
- {
- if (strcmp(uniCollection[i].name, uni) != 0)
- {
- continue;
- }
-
- uniFound = i;
- size_t studentsCount = uniCollection[i].studentsCount;
-
- for (size_t j = 0; j < studentsCount; j++)
- {
- if (uniCollection[i].collection[j].fn != fn)
- {
- continue;
- }
-
- studentFound = j;
- addStudentGrade(uniCollection[i].collection[j], grade);
- break;
- }
- break;
- }
-
- if (uniFound != -1 && studentFound != -1)
- {
- std::cout << std::endl << "Added: " << std::endl;
- print(uniCollection[uniFound].collection[studentFound]);
- }
- else
- {
- std::cout << std::endl << "No such student in this university" << std::endl;
- }
-}
-
-double getSuccess(const University uni)
-{
- double avarageGrade = 0;
- size_t studentsCount = uni.studentsCount;
-
- for (size_t i = 0; i < studentsCount; i++)
- {
- avarageGrade += uni.collection[i].averageGrade;
- }
-
- avarageGrade = avarageGrade / (double)(studentsCount);
-
- return avarageGrade;
-}
-
-void swapUniversities(University* uniCollection, const int& first, const int& second)
-{
- University temp = uniCollection[first];
- uniCollection[first] = uniCollection[second];
- uniCollection[second] = temp;
-}
-
-void sort(University* uniCollection, size_t unisCount)
-{
- //selection sort
- for (int pos = 0; pos < unisCount - 1; pos++)
- {
- int minimalIndex = pos;
-
- for (int i = pos; i < unisCount; i++)
- {
- int currSuccess = getSuccess(uniCollection[minimalIndex]);
- if (getSuccess(uniCollection[i]) > currSuccess)
- {
- minimalIndex = i;
- }
- }
-
- if (minimalIndex != pos)
- swapUniversities(uniCollection, pos, minimalIndex);
- }
-}
-
-int main()
-{
- //simple example:
-
- //creating university database:---------------
- University* uniCollection = new University[3];
-
- //FMI
- Student collection[3];
- collection[0] = createStudent("Angel", 81111, 6, 3);
- collection[1] = createStudent("Dimitar", 82222, 6, 2);
- collection[2] = createStudent("Anton", 83333, 6, 2);
-
- University FMI = createUniversity("FMI", collection, 3);
-
- //TU
- Student collectionTwo[4];
- collectionTwo[0] = createStudent("Vesko", 31244, 6, 6);
- collectionTwo[1] = createStudent("Ivan", 42342, 6, 6);
- collectionTwo[2] = createStudent("Mariano", 13433, 6, 6);
- collectionTwo[3] = createStudent("Gabriela", 43234, 6, 6);
-
- University TU = createUniversity("TU", collectionTwo, 4);
-
- //UNWE
- Student collectionThree[5];
- collectionThree[0] = createStudent("Chavdar", 13579, 6, 4);
- collectionThree[1] = createStudent("Stoino", 24680, 6, 4);
- collectionThree[2] = createStudent("Miss Playmate", 24567, 6, 4);
- collectionThree[3] = createStudent("ex fmi student", 12343, 6, 4);
- collectionThree[4] = createStudent("bukvalno vseki", 13333, 6, 5);
-
- University UNWE = createUniversity("UNWE", collectionThree, 5);
-
- uniCollection[0] = FMI;
- uniCollection[1] = TU;
- uniCollection[2] = UNWE;
- //-------------------------------------------------------------
-
- //functions:
- std::ofstream outFile("path.txt", std::ios::binary);
- saveUniversityToFile(outFile, uniCollection[1]);
- if (outFile.good() == 0)
- {
- std::cout << "Error saving the file";
- }
-
- outFile.close();
-
- std::ifstream inFile("path.txt", std::ios::binary);
- University example = readUniFromFile(inFile);
-
- if (inFile.good() == 0)
- {
- std::cout << "Error reading the file";
- }
-
- inFile.close();
-
- printUni(example);
-
- changeName(uniCollection, 3, "FMI", 83333, "Antoan");
- addGrade(uniCollection, 3, "FMI", 81111, 6);
-
- sort(uniCollection, 3);
-
- std::cout << "\nSorted:\n";
-
- for (int i = 0; i < 3; i++)
- {
- std::cout << i + 1 << ". " << uniCollection[i].name << std::endl;
- }
-
- for (int i = 0; i < 3; i++)
- {
- freeUni(uniCollection[i]);
- }
-}
|