Compilare: user.cpp: In function ‘int main()’: user.cpp:52:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("mxl.in", "rt", stdin); ^ user.cpp:53:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("mxl.out", "wt", stdout); ^ user.cpp:57:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &k); ^ user.cpp:59:43: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %s", &x, &y, formula); ^ user.cpp: In function ‘void eval(char*)’: user.cpp:43:19: warning: ‘current’ may be used uninitialized in this function [-Wmaybe-uninitialized] sum += current; ^