Brtdku

We have a square matrix A = [aij], where a number of lines and rows more than 3. Goal is: to find in matrix A position of table D [3;3], where the sum of the elements is the highest. Give this position by specifying the leftmost element's indices.

At the moment, what have i done: already wrote a code, which create a dimension array, and that all :C

int main() {

  int n;

  size_t height, weight;

  cout << "Input height and weight of your matrix:" << endl;

  cin >> dlina >> weight;

  int **a = new int*[height];

  for (int i = 0; i < height; i++)

    a[i] = new int[weight];



  for (int i = 0; i < height; i++)

    for (int j = 0; j < weight; j++) {

      cout << "Enter your matrix element: " << endl;

      cin >> a[i][j];

    }



  for (int i = 0; i < height; i++){ //i=0



    for (int j = 0; j < weight; j++) {//j=7

      cout << a[i][j] << " ";

    }



    cout << endl;



    }





  for (int i = 0; i < height; i++)

    delete a[i];

  delete a;





  cin >> n; 



  return 0;

}

A trivial solution doing minimal changes from your code including my previous remark :

#include <iostream>

using namespace std;



const int N = 3;



int sum(int * a, size_t i, size_t j)

{

  int n = 0;



  for (size_t ii = i; ii != i + N; ++ii)

    for (size_t jj = j; jj != j + N; ++jj)

      n += a[ii][jj];



  return n;

}



int main() {

  size_t height, width;

  cout << "Input height and width of your matrix:" << endl;

  cin >> height >> width;



  if ((height < N) || (width < N))

    return 0;



  int **a = new int*[height];

  for (size_t i = 0; i < height; i++)

    a[i] = new int[width];



  for (size_t i = 0; i < height; i++) {

    for (size_t j = 0; j < width; j++) {

      cerr << "Enter your matrix element: " << i << ' ' << j << ":";

      cin >> a[i][j];

    }

  }



  int max = sum(a, 0, 0);

  size_t maxi = 0, maxj = 0;



  for (size_t i = 1; i <= (height - N); i++){

    for (size_t j = 0; j <= (width - N); j++) {

      int s = sum(a, i, j);



      if (s > max) {

        max = s;

        maxi = i;

        maxj = j;

      }

    }

  }



  cout << maxi << ' ' << maxj << " : " << max << endl;



  for (size_t i = 0; i < height; i++)

    delete a[i];



  delete a;



  return 0;

}

Example of execution :

Input height and width of your matrix:

5 4

Enter your matrix element: 0 0:0

Enter your matrix element: 0 1:1

Enter your matrix element: 0 2:2

Enter your matrix element: 0 3:3

Enter your matrix element: 1 0:10

Enter your matrix element: 1 1:11

Enter your matrix element: 1 2:12

Enter your matrix element: 1 3:13

Enter your matrix element: 2 0:20

Enter your matrix element: 2 1:21

Enter your matrix element: 2 2:22

Enter your matrix element: 2 3:23

Enter your matrix element: 3 0:30

Enter your matrix element: 3 1:31

Enter your matrix element: 3 2:32

Enter your matrix element: 3 3:33

Enter your matrix element: 4 0:40

Enter your matrix element: 4 1:41

Enter your matrix element: 4 2:42

Enter your matrix element: 4 3:43

2 1 : 288

Note : this trivial solution can be optimized to not redo all the sum of cells each time the NxN matrices moves, I let you doing ...

Execution under valgrind :

==13767== Memcheck, a memory error detector

==13767== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.

==13767== Using Valgrind-3.13.0 and LibVEX; rerun with -h for copyright info

==13767== Command: ./a.out

==13767== 

Input height and width of your matrix:

5 4

Enter your matrix element: 0 0:0

Enter your matrix element: 0 1:1

Enter your matrix element: 0 2:2

Enter your matrix element: 0 3:3

Enter your matrix element: 1 0:10

Enter your matrix element: 1 1:11

Enter your matrix element: 1 2:12

Enter your matrix element: 1 3:13

Enter your matrix element: 2 0:20

Enter your matrix element: 2 1:21

Enter your matrix element: 2 2:22

Enter your matrix element: 2 3:23

Enter your matrix element: 3 0:30

Enter your matrix element: 3 1:31

Enter your matrix element: 3 2:32

Enter your matrix element: 3 3:33

Enter your matrix element: 4 0:40

Enter your matrix element: 4 1:41

Enter your matrix element: 4 2:42

Enter your matrix element: 4 3:43

2 1 : 288

==13767== 

==13767== HEAP SUMMARY:

==13767==     in use at exit: 0 bytes in 0 blocks

==13767==   total heap usage: 9 allocs, 9 frees, 22,372 bytes allocated

==13767== 

==13767== All heap blocks were freed -- no leaks are possible

==13767== 

==13767== For counts of detected and suppressed errors, rerun with: -v

==13767== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 6 from 3)