Compilare: user.cpp:1:2: warning: #import is a deprecated GCC extension [-Wdeprecated] #import<bits/stdc++.h> ^~~~~~ user.cpp:2:67: warning: ISO C++ forbids declaration of ‘main’ with no type [-Wreturn-type] std::ifstream f("euclid2.in");std::ofstream g("euclid2.out");main(){int a,b;for(f>>a;f>>a>>b;g<<std::__gcd(a,b)<<'\n');} ^