我讲一下我想到的 看看有没有遗漏

1. 不是 3 个 . 或者不是 1 个 :

2. 数字超过范围

3. 数字自然溢出了并刚好进 0 ~ 255 内

4. 前导零 (排除了单个 0 的情况)

5. 相邻符号

然后 WA 75

code:

#include <bits/stdc++.h>
using namespace std;

//int ip1, ip2, ip3, ip4, port;

class Address {
public:
	int ip1, ip2, ip3, ip4, port;
};

class Format {
private:
	int stringToInt(string s) {
		int res = 0, len = s.size();
		for (int i = 0; i < len; i++) {
			res = res * 10 + (s[i] - '0');
		}
		return res;
	}
	
	bool checkIp(int ip) {
		if (0 <= ip && ip <= 255) return true;
		return false;
	}
	
	bool checkPort(int port) {
		if (0 <= port && port <= 65535) return true;
		return false;
	}
public:
	bool checkAddr(string s) {
		string split[10];
		int cur = 0, len = s.size();
		int c1 = 0, c2 = 0;
		for (int i = 0; i < len; i++) {
			if (s[i] == '.') {
				cur++;
				c1++;
			} else if (s[i] == ':') {
				cur++;
				c2++;
			} else {
				split[cur] += s[i];
			}
			if (cur > 4) return false;
		}
//		cout << endl << c1 << endl << c2 << endl;
		if (c1 != 3 || c2 != 1) return false;
		Address res;
		for (int i = 0; i < 5; i++) {
			if (split[i].size() > 1) {
				if (split[i][0] == '0') return false;
			}
			if (split[i].size() > 6) return false;
			if (split[i].size() == 0) return false;
		}
		res.ip1 = stringToInt(split[0]);
		res.ip2 = stringToInt(split[1]);
		res.ip3 = stringToInt(split[2]);
		res.ip4 = stringToInt(split[3]);
		res.port = stringToInt(split[4]);
		return (checkIp(res.ip1) 
			&& checkIp(res.ip2) 
			&& checkIp(res.ip3) 
			&& checkIp(res.ip4) 
			&& checkPort(res.port));
	}
	
	Address parseAddr(string s) {
		string split[10];
		int cur = 0, len = s.size();
		for (int i = 0; i < len; i++) {
			if (s[i] == '.' || s[i] == ':') {
				cur++;
			} else {
				split[cur] += s[i];
			}
		}
		Address res;
		res.ip1 = stringToInt(split[0]);
		res.ip2 = stringToInt(split[1]);
		res.ip3 = stringToInt(split[2]);
		res.ip4 = stringToInt(split[3]);
		res.port = stringToInt(split[4]);
		return res;
	}
} format;

class Network {
private:
	map<string, int> servers;
public:
	int create(string addr, int id) {
		if (format.checkAddr(addr) == false) return 0;
		if (servers[addr] != 0) return 1;
		servers[addr] = id;
		return 2;
	}
	
	int connect(string addr) {
		return servers[addr];
	}
} network;

int n;
string s, add;

int main() {
//	scanf("%d.%d.%d.%d:%d", &ip1, &ip2, &ip3, &ip4, &port);
//	printf("%d %d %d %d %d", ip1, ip2, ip3, ip4, port);
//	cout << instance.stringToInt("123123");
//	Address a = instance.parseAddr("1.117.1.17:11117");
//	cout << a.ip1 << " " << a.ip2 << " " << a.ip3 << " " << a.ip4 << " " << a.port << endl;
//	cout << format.checkAddr("88.112.9.7:4294967300");
//	network.servers["123.123.123.1:1"] = 1;
//	cout << network.servers["123.123.123.1:2"];
	cin >> n;
	for (int i = 1; i <= n; i++) {
		cin >> s >> add;
		if (s == "Server") {
			int res = network.create(add, i);
			if (res == 0) {
				printf("ERR\n");
			} else if (res == 1) {
				printf("FAIL\n");
			} else if (res == 2) {
				printf("OK\n");
			}
		} else if (s == "Client") {
			if (format.checkAddr(add) == false) {
				printf("ERR\n");
			} else {
				int res = network.connect(add);
				if (res == 0) {
					printf("FAIL\n");
				} else {
					printf("%d\n", res);
				}
			}
		}
	}
}