Compilare: user.cpp: In function ‘void finds(int, int)’: user.cpp:24:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int idx=0;idx<v[key].size();idx++) ^ user.cpp: In function ‘int main()’: user.cpp:45:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ograzi.in","r",stdin); ^ user.cpp:47:14: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(str); ^ user.cpp:52:18: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(str); ^ user.cpp:61:18: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(str); ^ /tmp/ccHnC89b.o: In function `main': user.cpp:(.text.startup+0x66): warning: the `gets' function is dangerous and should not be used.