Compilare: user.cpp: In member function ‘void Huge::operator+=(int)’: user.cpp:20:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0, t = k; i < X.size(); i++) { ^ user.cpp: In member function ‘void Huge::operator*=(int)’: user.cpp:32:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0, t = 0; i < X.size(); i++) { ^ user.cpp: In function ‘int main()’: user.cpp:69:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("twosets.in", "r", stdin); ^ user.cpp:70:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("twosets.out", "w", stdout); ^ user.cpp:77:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &testCase); ^ user.cpp:82:19: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(BUFF); ^ user.cpp:98:19: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(BUFF); ^ /tmp/ccjRrRwM.o: In function `main': user.cpp:(.text.startup+0xed): warning: the `gets' function is dangerous and should not be used.