#include <stdio.h>
#include <stdlib.h>

void printMat(int mat[3][3],int nbLignes, int nbCols)
{
 int l,c;

 for(l=0;l<=nbLignes-1;l=l+1)
 {
  for(c=0;c<=nbCols-1;c=c+1)
  {
   if (c!=nbCols-1) { printf("%d ",mat[l][c]); }
   else             { printf("%d", mat[l][c]); }
  }
  printf("\n");
 }
}

void multiplicationMatCarree(int m1[3][3],int m2[3][3],int m[3][3],int n)
{
 int l,c,i;

 if (n==0) { printf("Attention, matrices vides\n"); exit(1); }

 for(l=0; l<=n-1; l=l+1)
 {
  for(c=0; c<=n-1; c=c+1)
  {
   m[l][c] = 0;
   for(i=0; i<=n-1; i=i+1)
   {
    m[l][c] = m[l][c] + m1[l][i]*m2[i][c];
   }
  }
 }
}

int main(void)
{
 int mat1[3][3] = {{1, 2, 3} , {4, 5, 6} , {7, 8, 9}};
 int mat2[3][3] = {{2, 0, 0} , {0, 2, 0} , {0, 0, 2}};
 int  mat[3][3];

 multiplicationMatCarree(mat1,mat2,mat,3);

 printf("\n");
 printf("Mat1:\n");
 printMat(mat1,3,3);
 printf("\n");

 printf("Mat2:\n");
 printMat(mat2,3,3);
 printf("\n");

 printf("Mat:\n");
 printMat(mat,3,3);
 printf("\n");

 return 0;
}