题目链接：https://vjudge.net/problem/UVA-814
题目翻译摘自《算法禁赛入门经典》
题目大意
本题的任务为模拟发送邮件时 MTA（邮件传输代理）之间的交互。所谓 MTA，就是 email地址格式 [email protected] 的“后面部分”。当某人从 [email protected] 发送给另一个人 [email protected] 时，这两个 MTA 将会通信。如果两个收件人属于同一个 MTA，发送者的 MTA 只需与这个 MTA 通信一次就可以把邮件发送给这两个人。
输入每个 MTA 里的用户列表，对于每个发送请求（输入发送者和接收者列表），按顺序输出所有 MTA 之间的 SMTP（简单邮件协议）交互。协议细节参见原题。
发送人 MTA 连接收件人 MTA 的顺序应该与在输入中第一次出现的顺序一致。
如果连接某个 MTA 之后发现所有收件人都不存在，则不应该发送DATA。所有用户名均 由不超过15个字母和数字组成。
发信人一定存在。
分析
略。
代码如下
1 #include <bits/stdc++.h>
2 using namespace std;
3
4 #define INIT() ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
5 #define Rep(i,n) for (int i = 0; i < (n); ++i)
6 #define For(i,s,t) for (int i = (s); i <= (t); ++i)
7 #define rFor(i,t,s) for (int i = (t); i >= (s); --i)
8 #define ForLL(i, s, t) for (LL i = LL(s); i <= LL(t); ++i)
9 #define rForLL(i, t, s) for (LL i = LL(t); i >= LL(s); --i)
10 #define foreach(i,c) for (__typeof(c.begin()) i = c.begin(); i != c.end(); ++i)
11 #define rforeach(i,c) for (__typeof(c.rbegin()) i = c.rbegin(); i != c.rend(); ++i)
12
13 #define pr(x) cout << #x << " = " << x << " "
14 #define prln(x) cout << #x << " = " << x << endl
15
16 #define LOWBIT(x) ((x)&(-x))
17
18 #define ALL(x) x.begin(),x.end()
19 #define INS(x) inserter(x,x.begin())
20
21 #define ms0(a) memset(a,0,sizeof(a))
22 #define msI(a) memset(a,inf,sizeof(a))
23 #define msM(a) memset(a,-1,sizeof(a))
24
25 #define MP make_pair
26 #define PB push_back
27 #define ft first
28 #define sd second
29
30 template<typename T1, typename T2>
31 istream &operator>>(istream &in, pair<T1, T2> &p) {
32 in >> p.first >> p.second;
33 return in;
34 }
35
36 template<typename T>
37 istream &operator>>(istream &in, vector<T> &v) {
38 for (auto &x: v)
39 in >> x;
40 return in;
41 }
42
43 template<typename T1, typename T2>
44 ostream &operator<<(ostream &out, const std::pair<T1, T2> &p) {
45 out << "[" << p.first << ", " << p.second << "]" << "\n";
46 return out;
47 }
48
49 inline int gc(){
50 static const int BUF = 1e7;
51 static char buf[BUF], *bg = buf + BUF, *ed = bg;
52
53 if(bg == ed) fread(bg = buf, 1, BUF, stdin);
54 return *bg++;
55 }
56
57 inline int ri(){
58 int x = 0, f = 1, c = gc();
59 for(; c<48||c>57; f = c==‘-‘?-1:f, c=gc());
60 for(; c>47&&c<58; x = x*10 + c - 48, c=gc());
61 return x*f;
62 }
63
64 template<class T>
65 inline string toString(T x) {
66 ostringstream sout;
67 sout << x;
68 return sout.str();
69 }
70
71 inline int toInt(string s) {
72 int v;
73 istringstream sin(s);
74 sin >> v;
75 return v;
76 }
77
78 typedef long long LL;
79 typedef unsigned long long uLL;
80 typedef pair< double, double > PDD;
81 typedef pair< int, int > PII;
82 typedef pair< int, PII > PIPII;
83 typedef pair< string, int > PSI;
84 typedef pair< int, PSI > PIPSI;
85 typedef set< int > SI;
86 typedef set< PII > SPII;
87 typedef vector< int > VI;
88 typedef vector< VI > VVI;
89 typedef vector< SI > VSI;
90 typedef vector< PII > VPII;
91 typedef map< int, int > MII;
92 typedef map< int, string > MIS;
93 typedef map< int, PII > MIPII;
94 typedef map< PII, int > MPIII;
95 typedef map< string, int > MSI;
96 typedef map< string, string > MSS;
97 typedef map< PII, string > MPIIS;
98 typedef map< PII, PII > MPIIPII;
99 typedef multimap< int, int > MMII;
100 typedef multimap< string, int > MMSI;
101 //typedef unordered_map< int, int > uMII;
102 typedef pair< LL, LL > PLL;
103 typedef vector< LL > VL;
104 typedef vector< VL > VVL;
105 typedef priority_queue< int > PQIMax;
106 typedef priority_queue< int, VI, greater< int > > PQIMin;
107 const double EPS = 1e-8;
108 const LL inf = 0x7fffffff;
109 const LL infLL = 0x7fffffffffffffffLL;
110 const LL mod = 1e9 + 7;
111 const int maxN = 1e4 + 7;
112 const LL ONE = 1;
113 const LL evenBits = 0xaaaaaaaaaaaaaaaa;
114 const LL oddBits = 0x5555555555555555;
115
116 struct User{
117 string mail, name, addr;
118
119 User() {}
120 User(string s) {
121 mail = s;
122 name = s.substr(0, s.find(‘@‘));
123 addr = s.substr(s.find(‘@‘) + 1);
124 }
125 };
126
127 MSS mta; // name->address
128
129 int main(){
130 //freopen("MyOutput.txt","w",stdout);
131 //freopen("input.txt","r",stdin);
132 //INIT();
133 string tmp, msg;
134 while(cin >> tmp) {
135 if(tmp == "*") break;
136 string loc;
137 int n;
138
139 cin >> loc >> n;
140 Rep(i, n) {
141 cin >> tmp;
142 mta[tmp] = loc;
143 }
144 }
145
146 while(cin >> tmp) {
147 if(tmp == "*") break;
148 User from(tmp);
149 vector< User > to;
150 map< string, VI > msv; // 顺序存相同地址的人
151 set< string > names; // 判重用
152
153 while(cin >> tmp) {
154 if(tmp == "*") break;
155 User t(tmp);
156
157 if(names.find(t.name) != names.end()) continue;
158 else names.insert(t.name);
159 to.PB(t);
160 msv[t.addr].PB(to.size() - 1);
161 }
162
163 getline(cin, msg); // ‘\n‘
164 while(getline(cin, tmp)) {
165 if(tmp == "*") break;
166 msg += " " + tmp + "\n";
167 }
168
169 foreach(i, to) {
170 if(msv.find(i->addr) != msv.end()) {
171 printf("Connection between %s and %s\n", from.addr.c_str(), i->addr.c_str());
172 printf(" HELO %s\n", from.addr.c_str());
173 printf(" 250\n");
174 printf(" MAIL FROM:<%s>\n", from.mail.c_str());
175 printf(" 250\n");
176
177 int cnt = 0;
178 foreach(j, msv[i->addr]) {
179 printf(" RCPT TO:<%s>\n", to[*j].mail.c_str());
180 if(mta.find(to[*j].name) != mta.end()) printf(" 250\n"), ++cnt;
181 else printf(" 550\n");
182 }
183 msv.erase(i->addr);
184
185 if(cnt) {
186 printf(" DATA\n");
187 printf(" 354\n");
188 printf("%s", msg.c_str());
189 printf(" .\n");
190 printf(" 250\n");
191 }
192
193 printf(" QUIT\n");
194 printf(" 221\n");
195 }
196 }
197 }
198 return 0;
199 }
UVA 814 The Letter Carrier's Rounds
原文地址：https://www.cnblogs.com/zaq19970105/p/11063869.html
时间： 2024-10-30 16:00:35