Compilare: user.cpp: In function ‘int main()’: user.cpp:64:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<strlen(s); i++) ^ user.cpp:61:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("expresie2.in","r",stdin); ^ user.cpp:62:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("expresie2.out","w",stdout); ^ user.cpp:63:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s",s); ^