生日礼物题-信封包装

#include<iostream>#include<map>using namespace std;int main(){int n, w, h;cin >> n >> w >> h;map<int, map<int, int>> M;int wi, hi;for (int i = 1; i <= n; ++i){cin >> wi >> hi;if ((wi>w) && (hi > h)){map<int, int> m;m.insert(pair<int, int>(i, hi));M.insert(pair<int, map<int, int>>(wi, m));}}if (M.size() == 0){cout << 0;exit(EXIT_FAILURE);}map<int, map<int, int>>::iterator It_first;map<int, map<int, int>>::iterator It_second;It_first = M.begin();It_second=++M.begin();map<int, int>::iterator it_first;map<int, int>::iterator it_second;while (It_second != M.end()){it_first = (It_first->second).begin();it_second = (It_second->second).begin();if ((it_second->second) <= (it_first->second))M.erase(It_second);++It_first;++It_second;}It_first = M.begin();cout << M.size() << endl;while(It_first!=M.end()){it_first = (It_first->second).begin();cout << it_first->first << " ";++It_first;}return 0;};