#include <iostream>
#include <vector>
#include <iomanip>

using namespace std;

void get_Matrix(vector<vector<float>>&  matrix, int n, int m);
void print_Matrix(vector<vector<float>> const&  matrix);
int amount_Of_Row(vector<vector<float>> const&  matrix);
float arithmetic_Mean(vector<vector<float>> const&  matrix, int zadana_velichyna);
void to_Triangular_View(vector<vector<float>>&  matrix);

int main()
{
   vector<vector<float>>  Matrix_Example = { {2, 3, 4, 1}, {1, 5, 2, 2}, {-3, 2, 1, 3}, {5, 4, 3, 2}};
   int n, m;
   cout <<"vedite kil'kist' ryudkiv: ";
   cin >> n;
   cout <<"vedite kil'kist' stovpchikiv: ";
   cin >> m;
   cout << endl;
   vector<vector<float>>  Matrix(n, vector<float>(m));
   get_Matrix(Matrix, n, m);
   print_Matrix(Matrix);
   cout <<"amount_Of_Row = " << amount_Of_Row(Matrix) << endl;
   int zadana_Velichyna;
   cout << "zadana_Velichyna = ";
   cin >> zadana_Velichyna;
   cout << "arithmetic_Mean = " << arithmetic_Mean(Matrix, zadana_Velichyna) << endl;

   to_Triangular_View(Matrix);

   print_Matrix(Matrix);
}

void get_Matrix(vector<vector<float>>&  matrix, int n, int m)
{
   float number = 0;
   for(int i = 0; i < n; i++)
      for(int j = 0; j < m; j++)
      {
         cin >> number;
         matrix[i][j] = number;
      }
};

void print_Matrix(vector<vector<float>> const&  matrix)
{
   for(auto element_vector : matrix)
   {
      for(auto element : element_vector)
         cout << setw(6) << setprecision(3) << element << " ";
      cout << endl;
   }
   cout << endl;
};

int amount_Of_Row(vector<vector<float>> const&  matrix)
{
   return matrix.size();
};

float arithmetic_Mean(vector<vector<float>> const&  matrix, int zadana_velichyna)
{
   int kilkist_spivpadin = 0; 
   float sum = 0;
   for(auto element_vector : matrix)
      for(auto element : element_vector)
      {
         if(element < zadana_velichyna)
         {
            sum += element;
            kilkist_spivpadin++;
         }
      }
   return sum / kilkist_spivpadin;
};

void to_Triangular_View(vector<vector<float>>&  matrix)
{
   int kilkist_stovpchikiv = matrix[0].size(), kilkist_ryadkiv = matrix.size();
   float  temp_koef = 0; 
   cout << "Size: " << kilkist_ryadkiv << "*" << kilkist_stovpchikiv << endl;
   

   for(int ryad = 0; ryad < kilkist_ryadkiv; ryad++)
   {
      for(int nast_ryad = ryad + 1; nast_ryad < kilkist_ryadkiv ; nast_ryad++)
      {
         temp_koef = matrix[nast_ryad][ryad] / matrix[ryad][ryad];
         for(int stovp = 0; stovp < kilkist_stovpchikiv; stovp++)
         {
            matrix[nast_ryad][stovp] = matrix[nast_ryad][stovp] - temp_koef * matrix[ryad][stovp];
         }
      }
      
   }
};