/in/foo.cc: In function 'int main()':
/in/foo.cc:22:21: warning: overflow in implicit constant conversion [-Woverflow]
         dk[i].tanmu=1e18;
                     ^~~~
/in/foo.cc:26:18: warning: overflow in implicit constant conversion [-Woverflow]
         int maxn=1e18;
                  ^~~~
/in/foo.cc:32:13: warning: 'v' may be used uninitialized in this function [-Wmaybe-uninitialized]
         f[v]=1;
         ~~~~^~