Compilare: main.cpp: In function 'int main()': main.cpp:30:103: warning: operation on 'matrix[(i + 2)][(j + 3)]' may be undefined [-Wsequence-point] matrix[i + 1][j + 1] = matrix[i + 2][j + 1] = matrix[i + 2][j + 2] = matrix[i + 2][j + 3] = matrix[i + 2][j + 3] = matrix[i + 1][j + 3] = id; ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~