HJ18 识别有效的IP地址和掩码并进行分类统计

HJ18 识别有效的IP地址和掩码并进行分类统计

#include <iostream>
#include <sstream>
#include <string>
#include <vector>

// #define DEBUG

#ifdef DEBUG
#include <fstream>
#endif

using namespace std;

class HJ18 {
private:
    int a, b, c, d, e, x, p;

    static unsigned str2unsigned(std::string s) {
        unsigned m = 0;
        for (int i = 0; i < s.size(); i++) {
            m = 10 * m + s.at(i) - '0';
        }
        return m;
    }
    static bool isValidMask(unsigned mask) {
        // 二进制下全是1或者全是0均为非法子网掩码
         if (0 == mask || mask == 0xffffffff) {
            return false;
        }
        int i;
        for (i = 31; i >=0; i--) {
            if ((mask & (1<<i)) == 0) {
                break;  // 找到变成0的位置
            }
        }
        while (--i >= 0) {
            if ((mask & (1<<i))) {
                return false;  // 0->1
            }
        }
        return true;
    }
public:
    HJ18() {
        this->a = this->b = this->c = this->d = this->e = this->x = this->p = 0;
    }

    HJ18 add(string input) {
        vector<string> vs = split(std::move(input), '~');

#ifdef DEBUG
        cout.setf(ios::showbase);
        std::cout << "ip=" <<vs[0] << ", mask=" << vs[1] << std::endl;
#endif
        unsigned ip, mask;
        try {
            ip = ip2long(vs[0]);
            mask = ip2long(vs[1]);
        } catch (bad_exception &e) {
            this->x += 1;
            return *this;
        }
#ifdef DEBUG
        std::cout << "ip=" << hex <<ip <<std::endl;
        std::cout << "mask=" <<hex <<mask <<std::endl;
#endif

        unsigned fb = (ip >> 24) & 0x000000ff;  // first byte
        unsigned nb = (ip >> 16) & 0x000000ff; // second byte
        // 类似于【0.*.*.*】和【127.*.*.*】的IP地址不属于上述输入的任意一类，也不属于不合法ip地址，计数时请忽略
        if (fb == 0 || fb == 127) {
            return *this;
        }
        if (!isValidMask(mask)) {
            this->x += 1;
            return *this;
        }

        if (fb < 127) {
            this->a += 1;
            if (fb == 10) {
                this->p += 1;
            }
            // std::cout << "A class\n";
        } else if (fb < 192) {
            this->b += 1;
            if (fb == 172 && (16<=nb && nb < 32)) {
                this->p += 1;
            }
            // std::cout << "B class\n";
        } else if (fb < 224) {
            this->c += 1;
            // std::cout << "C class " << "fb="<<fb <<",nb="<<nb<< std::endl;
            if (fb == 192 && nb == 168) {
                this->p += 1;
            }
        } else if (fb < 240) {
            this->d += 1;
        } else {
            this->e += 1;
        }

        return *this;
    }

    string toString() const {
        stringstream ss;
        ss << a << " "<< b << " " << c << " " << d << " " << e << " "<< x << " " << p;
        string s = ss.str();
        ss.clear();
        return s;
    }

    static unsigned int ip2long(string s) {
        vector<string> vs = split(std::move(s), '.');
        unsigned int  ip = 0;
        unsigned u;
        for (auto & v : vs) {
            if (v.empty()) {
                throw bad_exception();
            }
            u = str2unsigned(v);
            if (u < 0 || u > 255) {
                throw bad_exception();
            }
            ip = (ip << 8) | u;
        }
        return ip;
    }
    static vector<string> split(string s, char delim) {
        vector<string> vec;
        int i;
        int subLen = 0;
        int len = s.size();
        for (i = 0; i < len; i++) {
            if (s.at(i) != delim) {
                subLen += 1;
                continue;
            }
            vec.push_back(s.substr(i-subLen, subLen));
            subLen = 0;
        }
        vec.push_back(s.substr(i-subLen, subLen));
        return vec;
    }
};

int main() {
    HJ18 solution;
    string line;
#ifndef DEBUG
    while (cin >> line) {
        solution.add(line);
    }
#else
    std::ifstream ifs;
    ifs.open("../input4.txt", std::ios_base::in);
    if (!ifs.is_open()) {
        std::cout << "打开../input4.txt失败";
        return -2;
    }
    int i = 0;
    while (ifs >> line) {
        solution.add(line);
        cout.unsetf(ios::hex);
        std::cout <<"----------"<<++i<<"-------------\n";
    }
    ifs.close();
#endif
    cout << solution.toString() << endl;
}