Compilare: user.cpp: In function ‘int main()’: user.cpp:82:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < ans.size(); ++i) ^ /tmp/ccsJWFLT.o: In function `read()': user.cpp:(.text+0xb): warning: the `gets' function is dangerous and should not be used.