Test1

#include <iostream>
#define _USE_MATH_DEFINES
#include <math.h>
#include <cstdlib>
using namespace std;


int Sorting()
{
    int* arr;
    int size;
    cout << "n = ";
    cin >> size;
    arr = new int[size];

    for (int i = 0; i < size; i++) {
        arr[i] = rand() % 100 + 1;
    }

    cout << "no sort:" << endl;
    for (int i = 0; i < size; i++) {
        cout << arr[i] << " ";
    }


    int temp;
    for (int i = 0; i < size - 1; i++) {
        for (int j = 0; j < size - i - 1; j++) {
            if (arr[j] > arr[j + 1]) {
                temp = arr[j];
                arr[j] = arr[j + 1];
                arr[j + 1] = temp;
            }
        }
    }
    cout << "\nsort: " << endl;
    for (int i = 0; i < size; i++) {
        cout << arr[i] << " ";
    }
    cout << endl;

    return 0;
}


int Matrix_multiplication()
{
    int row1, row2, col1, col2;
    double** a, **b, **c;

    cout << "row1: ";
    cin >> row1;
    cout << "col1: ";
    cin >> col1;
    cout << "row2: ";
    cin >> row2;
    cout << "col2: ";
    cin >> col2;
    if (col1 != row2)
    {
        cout << "multiplication is not possible!";
        cin.get(); cin.get();
        return 0;
    }
    // эл. первой матрицы. ввод
    a = new double* [row1];
    cout << "elements 1" << endl;
    for (int i = 0; i < row1; i++)
    {
        a[i] = new double[col1];
        for (int j = 0; j < col1; j++)
        {
            cout << "a[" << i << "][" << j << "]= ";
            cin >> a[i][j];
        }
    }
    // эл. первой матрицы. вывод
    for (int i = 0; i < row1; i++)
    {
        for (int j = 0; j < col1; j++)
            cout << a[i][j] << " ";
        cout << endl;
    }
    // эл. второй матрицы. ввод
    b = new double* [row2];
    cout << "elements 2" << endl;
    for (int i = 0; i < row2; i++)
    {
        b[i] = new double[col2];
        for (int j = 0; j < col2; j++)
        {
            cout << "b[" << i << "][" << j << "]= ";
            cin >> b[i][j];
        }
    }
    // эл. второй матрицы. вывод
    for (int i = 0; i < row2; i++)
    {
        for (int j = 0; j < col2; j++)
        {
            cout << b[i][j] << " ";
        }
        cout << endl;
    }
    // Умножение
    c = new double* [row1];
    for (int i = 0; i < row1; i++)
    {
        c[i] = new double[col2];
        for (int j = 0; j < col2; j++)
        {
            c[i][j] = 0;
            for (int k = 0; k < col1; k++)
                c[i][j] += a[i][k] * b[k][j];
        }
    }
    // Вывод матрицы произведения
    cout << "result" << endl;
    for (int i = 0; i < row1; i++)
    {
        for (int j = 0; j < col2; j++)
            cout << c[i][j] << " ";
        cout << endl;
    }
    cin.get(); cin.get();
    return 0;


}
int Solve_integral1()
{
    double a = 0;
    double b = M_PI/2;
    int n = 2;

    double h = (b - a) / n;
    double c = a + h;
    double result = 0;


    result += (pow(cos(3 * a), 3) * sin(6 * a));
    for (int i = 0; i < n; i++)
    {
        result += h*(pow(cos(3 * c), 3) * sin(6 * c));
        c += h;
    }
    cout << "метод прямоугольников:" << endl;
    cout << result << endl;

    c = a + h;
    result = ((pow(cos(3 * a), 3) * sin(6 * a))+
        (pow(cos(3 * b), 3) * sin(6 * b)))/2;
    for (int i = 0; i < n; i++)
    {
        result += (pow(cos(3 * c), 3) * sin(6 * c));
        c += h;
    }
    result *= h;
    cout << "метод трапеций:" << endl;
    cout << result << endl;

    return 0;
}


int main()
{

    setlocale(LC_ALL, "Russian");

    cout << "Что будем делать?\n1. Умножение матриц\n2. Умножение вектора на матрицу \n3. Сортировка \n4. Интегралы" << endl;
    int choise = 0;
    cin >> choise;
    if (choise == 1 || choise == 2)
    {
        Matrix_multiplication();
    }
    if (choise == 3)
    {
        Sorting();
    }
    if (choise == 4)
    {
        Solve_integral1();
    }



}