题目 思路: #include <bits/stdc++.h>using namespace std;// #define int long long#define pb push_back#define fi first#define se second#define lson p << 1#define rson p << 1 | 1const int maxn
先上题目。 For an electronic mail application you are to describe the SMTP-based communication that takes place between pairs of MTAs. The sender’s User Agent gives a formatted message to the sending Mes