int i,j,k;
double a[N][N], b[N][N], c[N][N];
// initializarea matricelor a si b
for (i=0;i<N;i++){
   for (j=0;j<N;j++){
      c[i][j] = 0.0;
      for (k=0;k<N;k++){
	c[i][j] += a[i][k] * b[k][j];
      }
   }
}