Compilare: user.cpp: In function ‘void readFile()’: user.cpp:31:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d", &n); ^ user.cpp: In function ‘void solve()’: user.cpp:115:95: warning: ‘lastk’ may be used uninitialized in this function [-Wmaybe-uninitialized] col[last] = lin[lastk] = diag1[last - lastk + n] = diag2[lastk + last - 1] = 0; ^ user.cpp:115:95: warning: ‘last’ may be used uninitialized in this function [-Wmaybe-uninitialized]