ccf csp 201812-3 CIDR合并

我使用了to_string()函数，所以提交的时候，请选择c++11标准，不然会出现编译报错。

先附上80分代码，之后再补完整版。

#include<iostream>
#include<vector>
#include<set>
#include<string>
#include<algorithm>
#include<cctype>
using namespace std;

class IP{
public:
    string s;
    string binary;
    int pre;
    IP(){
        this->binary = "";
    }
};

int n;
IP ip[10000];
set<int> del;

void reform(int);
string tobinary(int);
bool cmp(const IP &, const IP &);
void merge();

int main(){
    cin >> n;
    for(int i = 0; i < n; i++){
        cin >> ip[i].s;
        reform(i);
    }
    sort(ip, ip + n, cmp);

    merge();
    for(int i = 0; i < n; i++){
        if(del.find(i) != del.end()) continue;
        cout << ip[i].s << '/' << ip[i].pre << endl;
    }

    return 0;
}

void reform(int i){
    int point = count(ip[i].s.begin(), ip[i].s.end(), '.');
    int slash = count(ip[i].s.begin(), ip[i].s.end(), '/');
    if(point < 3 && slash == 1){
        string add = "";
        for(int j = point; j < 3; j++){
            add += ".0";
        }
        ip[i].s = ip[i].s.substr(0, ip[i].s.find_first_of('/'))
            + add + ip[i].s.substr(ip[i].s.find_first_of('/'));
    }else if(slash == 0){
        string add = "";
        for(int j = point; j < 3; j++){
            add += ".0";
        }
        ip[i].s = ip[i].s + add + '/' + to_string((point + 1) * 8);
    }
    for(int j = 0, k = 0; ; ){
        if(ip[i].s[k] == '.'){
            ip[i].binary += tobinary(atoi(ip[i].s.substr(j, k - j).c_str()));
            j = k++ + 1;
        }else if(ip[i].s[k] == '/'){
            ip[i].binary += tobinary(atoi(ip[i].s.substr(j, k - j).c_str()));
            break;
        }else{
            k++;
        }
    }
    ip[i].pre = atoi(ip[i].s.substr(ip[i].s.find_first_of('/') + 1).c_str());
    ip[i].s = ip[i].s.substr(0, ip[i].s.find_first_of('/'));
}

string tobinary(int num){
    string res = "";
    while(num != 0){
        res = (num % 2 == 1 ? "1" : "0") + res;
        num /= 2;
    }
    for(int i = res.length(); i < 8; i++){
        res = "0" + res;
    }
    return res;
}

bool cmp(const IP &a, const IP &b){
    if(a.binary != b.binary){
        return a.binary < b.binary;
    }else{
        return a.pre < b.pre;
    }
}

void merge(){
    if(n == 1) return;
    for(int i = 0, j = 1; j < n; j++){
        if(ip[i].pre <= ip[j].pre
            && ip[i].binary.substr(0, ip[i].pre)
                == ip[j].binary.substr(0, ip[i].pre)){
            del.insert(j);
        }else{
            i = j;
        }
    }

    // if(n - del.size() == 1) return;
    // for(int i = 0, j = 1; j < n; ){
    //     if(del.find(j) != del.end()){
    // 
    //     }else{
    // 
    //     }
    // }
}