src.cpp: In function 'int main()':
src.cpp:8:33: error: 'stdin' was not declared in this scope
freopen("GHEPHINH.INP","r",stdin);
^
src.cpp:8:38: error: 'freopen' was not declared in this scope
freopen("GHEPHINH.INP","r",stdin);
^
src.cpp:9:33: error: 'stdout' was not declared in this scope
freopen("GHEPHINH.OUT","w",stdout);
^