# include & lt; Hash_map & gt; 
# include & lt; Cstdio> 
# include & lt; Iostream> 

using namespace std; 
Using the namespace __gnu_cxx; 

Const int NODE_HASH=13333331; 
Struct Node {
int a, b; 
}; 
Struct Node_hash {
Size_t operator () (const Node& RHS) const {
Return RHS. A * RHS. B % NODE_HASH; 
} 
}; 
///the return value type size_t for 
Struct Node_equal {
Boolean operator () (const Node & amp; X, const Node & amp; Y) const {
Return x.a==y.a & amp; & X.b==y.b; 
} 
}; 

Int main () 
{
Hash_map & lt; The Node, int, Node_hash, Node_equal & gt; HMP; 
return 0; 
}