若干问题：
struct Node { int k, b; friend bool operator <(Node a, Node b) { return a.k < b.k; } }node1, node2; map<Node, int> mp; int main() { node1.k = 1; node1.b = 1; mp[node1] = 1; node1.k = 1; node1.b = 2; printf("%d\n", mp.count(node1)); //输出1 return 0; }