P1.cpp:5:19: error: conflicting declaration ‘typedef long long int int64_t’
typedef long long int64_t;
^
In file included from /usr/lib/gcc/x86_64-linux-gnu/4.9/include/stdint.h:9:0,
from /usr/include/c++/4.9/cstdint:41,
from /usr/include/c++/4.9/bits/char_traits.h:380,
from /usr/include/c++/4.9/ios:40,
from /usr/include/c++/4.9/ostream:38,
from /usr/include/c++/4.9/iostream:39,
from P1.cpp:1:
/usr/include/stdint.h:40:19: note: previous declaration as ‘typedef long int int64_t’
typedef long int int64_t;
^