#include <iostream>
#include <iomanip>

using namespace std;

//on ne peut pas changer la taille de la matrice pendant l'execution,
//donc on assume une taille maximale de N * N    
const int N = 100;

void prodMat(double mat1[][N], double mat2[][N], double matR[][N], int n);
void diffMat(double mat1[][N], double mat2[][N], double matR[][N], int n);
void addMat(double mat1[][N], double mat2[][N], double matR[][N], int n);
void imprimeMat(double mat[][N], int n);

int main() {
  double mat1[N][N] = {0.};
  double mat2[N][N] = {0.};
  double matR[N][N] = {0.};
  
  int n;
  cout << "Entrez la taille de la matrice (max. 100) ?";
  cin >> n;

  cout << "Entrez les " << n*n << " elements de la matrice :" << endl;
  for (int i=0; i<n; i++)
    for (int j=0; j<n; j++)
      cin >> mat1[i][j];
  cout << "et de la deuxieme matrice :" << endl;
  for (int i=0; i<n; i++)
    for (int j=0;j<n;j++)
      cin >> mat2[i][j];

  int opera;
  do {
    cout << "Choisissez une operation :" << endl;
    cout << "1: addition, 2: soustraction:, 3: multiplication !";
    cin >> opera;
    if(opera>3 || opera<1)
      cout << "Vous n'avez pas choisi une option valide !" << endl;
   } while(opera>3 || opera<1);

  switch(opera) {
    case 1:
      addMat(mat1,mat2,matR,n);
      break;
    case 2:
      diffMat(mat1,mat2,matR,n);
      break;
    case 3:
      prodMat(mat1,mat2,matR,n);
      break;
  }

  cout << "La premiere matrice" << endl;
  imprimeMat(mat1,n);
  cout << "La deuxieme matrice" << endl;
  imprimeMat(mat2,n);
  cout << "et le resultat de la";
  switch(opera) {
    case 1:
      cout << " addition." << endl;
      break;
    case 2:
    cout << " soustraction." << endl;
      break;
    case 3:
      cout << " multiplication." << endl;
      break;
  }  
  imprimeMat(matR,n);

  return 0;
}

void prodMat(double mat1[][N], double mat2[][N], double matR[][N], int n) {
  for (int i=0; i<n; i++)
    for (int j=0; j<n; j++)
      for (int k=0; k<n; k++)
	    matR[i][j] += mat1[i][k] * mat2[k][j];
}

void diffMat(double mat1[][N], double mat2[][N], double matR[][N], int n) {
  for (int i=0; i<n; i++)
    for (int j=0; j<n; j++)
   	  matR[i][j] = mat1[i][j] - mat2[i][j];
}

void addMat(double mat1[][N], double mat2[][N], double matR[][N], int n) {
  for (int i=0; i<n; i++)
    for (int j=0; j<n; j++)
   	  matR[i][j] = mat1[i][j] + mat2[i][j];
}

void imprimeMat(double mat[][N], int n) {
  cout << setw(5) << "/" << setw(n*10+5) << "\\" << endl;
  for(int i=0; i<n; i++) {
    cout << setw(5) << "|";
    for(int j=0; j<n; j++)
      cout << setw(10) << setprecision(5) << mat[i][j];
    cout<<setw(5)<<"|"<<endl;
  }
  cout << setw(5) << "\\" << setw(n*10+5) << "/" << endl;
}