Sort in descending order the array elements that belong to the shaded area-CodePudding

#include <iostream>
#include <cmath>
#include <stdlib.h>
#include <iomanip>
using namespace std;
 
int **CreateMatrix (int rows, int cols);
void FillMatrix (int **matrix, int rows, int cols);
void OutputMatrix (int **matrix, int rows, int cols);
void SortMatrix (int **matrix, int rows, int cols);
void DellMatrix(int **matrix, int rows);
 
int main(){
 
    srand(time(NULL));
 
    int rows = 9, cols = 9;
 
    int **matrix = CreateMatrix(rows, cols);
    FillMatrix(matrix, rows, cols);
    cout << "Цикл до сортування: " << endl;
    OutputMatrix(matrix, rows, cols);
 
    cout << endl;
    SortMatrix(matrix, rows, cols);
    cout << "Цикл після сортування: " << endl;
    OutputMatrix(matrix, rows, cols);
    DellMatrix(matrix, rows);
 
 
    system("pause");
    return 0;
}
 
 
 
int **CreateMatrix(int rows, int cols){    
 
    int **matrix = new int *[rows];
 
    for (int i = 0; i < rows; i  )
    {
        matrix[i] = new int [cols];
 
    }
    return matrix;
 
}
 
void FillMatrix(int **matrix, int rows, int cols){
 
    int N = 19; 
 
    for (int i = 0; i < rows; i  ) {
        for (int j = 0; j < cols; j  ) {
 
            matrix[i][j] = N; 
 
        }
    }
 
    for (int i = rows - 1; i > rows / 2 - 1; i--)
    {
        for (int k = cols - 1 - i; k < 1   i; k  ) 
           
        {
            matrix[i][k] = rand() % 100; 
        }
 
 
    }
}
 
void OutputMatrix(int **matrix, int rows, int cols){
 
    for (int i = 0; i < rows; i  )
    {
        for (int j = 0; j < cols; j  )
        {
 
            cout << setw(5) << matrix[i][j];
 
        }
        cout << endl;
    }
}
 
void SortMatrix (int **matrix, int rows, int cols){ //selection sort 
 
    int max, maxi;
 
    for (int k = rows - 1; k > rows / 2 - 1; k--) 
    {                                            
        for (int i = cols - 1 - k; i < 1   k; i  ) 
        {
 
            max = matrix[k][i]; 
            maxi = i; 
 
 
            for (int j = i   1; j <= k; j  )
               
            {
 
                if (matrix[k][j] > max) 
                {
                    max = matrix[k][j]; 
                    maxi = j;           
                }
            }
 
            matrix[k][maxi] = matrix[k][i]; 
            matrix[k][i] = max; 
           
        }
 
    }
}
 
void DellMatrix(int **matrix, int rows){
 
    for (int i = 0; i < rows; i  )
    {
        delete matrix[i];
    }
    delete[] matrix;
 
}

Цикл до сортування: 
  19   19   19   19   19   19   19   19   19
  19   19   19   19   19   19   19   19   19
  19   19   19   19   19   19   19   19   19
  19   19   19   19   19   19   19   19   19
  19   19   19   19   64   19   19   19   19
  19   19   19   64   47   94   19   19   19
  19   19   59    5   54   70    4   19   19
  19   56   21   49   45   17   87   61   19
  48    3    5   33   40   70   84   46   68

Цикл після сортування: 
  19   19   19   19   19   19   19   19   19
  19   19   19   19   19   19   19   19   19
  19   19   19   19   19   19   19   19   19
  19   19   19   19   19   19   19   19   19
  19   19   19   19   64   19   19   19   19
  19   19   19   94   64   47   19   19   19
  19   19   70   59   54    5    4   19   19
  19   87   61   56   49   45   21   17   19
  84   70   68   48   46   40   33    5    3

Hi all, Task: The elements in the shaded area are generated randomly. All others = N. Arrange the elements in the shaded area in descending order. I did a sort in rows, but I need all elements in general to be sorted in descending order, i.e. at the top the biggest elements, below the smallest. I can not figure out how to re-do it, hope for your help! Thank you.

CodePudding user response：

I would do it like that:

int NumberOfValues(int cols)
{
    int count = 0;
    for (int i = cols; i > 0; i -=2)
        count  = i;
    return count;
}

void FillMatrix(int **matrix, int rows, int cols){

    int N = 19;

    for (int i = 0; i < rows; i  ) {
        for (int j = 0; j < cols; j  ) {
            matrix[i][j] = N;
        }
    }

    std::vector<int> random_numbers(NumberOfValues(cols));
    for (auto &i : random_numbers)
        i = rand() % 100;

    std::sort(begin(random_numbers), end(random_numbers));
    int index = 0;
    for (int i = rows - 1; i > rows / 2 - 1; i--)
    {
        for (int k = cols - 1 - i; k < 1   i; k  )
        {
            matrix[i][k] = random_numbers[index  ];
        }
    }
}

make an array (a std::vector is perfect for that) with the correct number of values in the pyramid (for 9 cols you have 9 values in the last row, 7 above that, 5 above the 7, 3 above the 5 and 1 above the 3, so 9 7 5 3 1), fill it with random numbers, sort it and then use these values instead of random numbers.

In your del function you forgot to use delete[] matrix[i]; instead of delete matrix[i];. A new[] needs a delete[].

Running example: https://godbolt.org/z/o34vncYor

CodePudding user response：

#include <iostream>
#include <cmath>
#include <stdlib.h>
#include <iomanip>
using namespace std;

int **CreateMatrix (int rows, int cols);
void FillMatrix (int **matrix, int rows, int cols);
void OutputMatrix (int **matrix, int rows, int cols);
void SortMatrix (int **matrix, int rows, int cols);
void DellMatrix(int **matrix, int rows);

int main(){

    srand(time(NULL));

    int rows = 9, cols = 9;

    int **matrix = CreateMatrix(rows, cols);
    FillMatrix(matrix, rows, cols);
    cout << "Цикл до сортування: " << endl;
    OutputMatrix(matrix, rows, cols);

    cout << endl;
    cout << "Цикл після сортування: " << endl;
    OutputMatrix(matrix, rows, cols);
    DellMatrix(matrix, rows);


    system("pause");
    return 0;
}



int **CreateMatrix(int rows, int cols){     

    int **matrix = new int *[rows];

    for (int i = 0; i < rows; i  )
    {
        matrix[i] = new int [cols];

    }
    return matrix;

}

void FillMatrix(int **matrix, int rows, int cols){

    int N = 19, size = 25;
    int matrix2[size];

    int tmp;

    for (int l = 0; l < size; l  ) {
        matrix2[l] = rand() % 100;
    }

    for(int i = 0; i < size; i  )
    {
        int pos = i;
        tmp = matrix2[i];
        for(int j = i   1; j < size; j  )
        {
            if (matrix2[j] > tmp)
            {
                pos = j;
                tmp = matrix2[j];
            }
        }
        matrix2[pos] = matrix2[i];
        matrix2[i] = tmp;
    }

    for (int p = 0; p < size; p  ) {
        cout << matrix2[p] << " ";
    }
    cout << endl;


    for (int i = 0; i < rows; i  ) {
        for (int j = 0; j < cols; j  ) {

            matrix[i][j] = N; 

        }
    }

    for (int i = rows - 1; i > rows / 2 - 1; i--)
       
    {
        for (int k = cols - 1 - i; k < 1   i; k  ) 
           
        {

            for (int j = 0; j < rows; j  ) {
                matrix[i][k] = matrix2[j]; 
            }

        }


    }
}

void OutputMatrix(int **matrix, int rows, int cols){

    for (int i = 0; i < rows; i  )
    {
        for (int j = 0; j < cols; j  )
        {

            cout << setw(5) << matrix[i][j];

        }
        cout << endl;
    }
}

void DellMatrix(int **matrix, int rows){

    for (int i = 0; i < rows; i  )
    {
        delete matrix[i];
    }
    delete[] matrix;

}

98 97 92 92 89 89 81 78 76 74 69 31 31 29 26 22 21 17 17 9 6 4 1 0 0 
Цикл до сортування: 
   19   19   19   19   19   19   19   19   19
   19   19   19   19   19   19   19   19   19
   19   19   19   19   19   19   19   19   19
   19   19   19   19   19   19   19   19   19
   19   19   19   19   76   19   19   19   19
   19   19   19   76   76   76   19   19   19
   19   19   76   76   76   76   76   19   19
   19   76   76   76   76   76   76   76   19
   76   76   76   76   76   76   76   76   76

Цикл після сортування: 
   19   19   19   19   19   19   19   19   19
   19   19   19   19   19   19   19   19   19
   19   19   19   19   19   19   19   19   19
   19   19   19   19   19   19   19   19   19
   19   19   19   19   76   19   19   19   19
   19   19   19   76   76   76   19   19   19
   19   19   76   76   76   76   76   19   19
   19   76   76   76   76   76   76   76   19
   76   76   76   76   76   76   76   76   76

This is another option, but it does not work correctly