Compilare: user.cpp: In function ‘void read()’: user.cpp:15:19: warning: format ‘%s’ expects argument of type ‘char*’, but argument 2 has type ‘char (*)[100005]’ [-Wformat=] scanf("%s", &s); ^ user.cpp:14:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("expr.in", "r", stdin); ^ user.cpp:15:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s", &s); ^ user.cpp: In function ‘void write()’: user.cpp:138:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("expr.out", "w", stdout); ^