本地编译结果两个： 1、//*********** 5 at touch cheat choose tact a 23 2、//*********** 3 aaa aaaa aaaaa a 19

以下是源代码：

#include<iostream>
#include<list>
#include<string>
#include<QCoreApplication>

using namespace std;

class word{
private:
    list<word*> nextWord_List; //以该词的末尾一部分为开头的其他单词组成的链表
    list<int> nextLen;//插入下个单词增加的长度，是下个单词的长度减去重合长度
    string * str;
    int count; //本单词在龙中出现的次数

public:
    word():count(0){}
    void countEsc(){count++;}
    void countDesc(){count--;}
    bool count_In_Range(){return count<2;}
    string * getStr()const{return str;}
    void setStr(string *str){this->str=str;}
    void clearStr(){//清除字符串
        delete str;
        str=nullptr;
    }
    list<word*>* getList(){return &nextWord_List;}
    list<int>* getNextLen(){return &nextLen;}
    //int getLen()const{return  len;}
    void getAllWord_which_StartWithThisEnd(word * const allWord,int count){
        for(int i=1;i<(int)str->size();i++){//  i确定子串
            for(int j=0;j<count;j++){//  j确定其他单词
                string *ortherStr=allWord[j].getStr();
                string SubStr=str->substr(i);//SubStr-子串
                if(
                        ortherStr->substr(0,SubStr.size())==SubStr   //其他字符串以子串开头
                        && SubStr.size()!=ortherStr->size()
                        )
                {
                    //nextLen.push_back(ortherStr->size()-SubStr.size());
                    nextWord_List.push_back(allWord+j);
                }
            }
        }

        //检查下家和上家的最大合并，例如 aaa 和 aaaa 合并有两种方式，但最大合并是 3a+4a=6a
        for(auto it=nextWord_List.begin();it!=nextWord_List.end();it++){
            int len;
            for(int i=1;i<(int)str->size();i++){
                string SubStr=str->substr(i);
                if(SubStr == (*it)->getStr()->substr(0,SubStr.size()))
                    len=(*it)->getStr()->size()-SubStr.size();
            }
            nextLen.push_back(len);
        }
    }
};

int MaxLength=0;
list<word*> dragon;

void creatDragon(list<word*>* newWords,list<int> *nextLen){
    static int length=0;
    //bengin 造龙******************************
    auto it=newWords->begin();
    auto itLen=nextLen->begin();
    for(;it!=newWords->end();){
        word *nextWord=*it;
        bool FlagPush;
        if(nextWord->count_In_Range()){
            dragon.push_back(nextWord);
            FlagPush=true;
            nextWord->countEsc();
            length+=(*itLen);
            creatDragon(nextWord->getList(),nextWord->getNextLen());//放入新词后,继续检索新词的“次词”
        }else FlagPush=false;

        if(FlagPush){
            dragon.pop_back();
            (*it)->countDesc();
            length-=(*itLen);
        }
        it++;
        itLen++;
    }
    //end 造龙*********************************

    //begin 比较本次龙的长度*********************
    if(length>MaxLength)MaxLength=length;

};

int main(){

    int N;
    cin>>N;
    word allWord[N];
    string *str=new string[N];
    for(int i=0;i<N;i++){
        cin>>str[i];
        allWord[i].setStr(str+i);
    }
    char beginChar;
    cin>>beginChar;


    //初始化所有单词的“下家”
    for(int i=0;i<N;i++) allWord[i].getAllWord_which_StartWithThisEnd(allWord,N);

    {//检测获取list<word*>的准确性
        //                    for(int i=0;i<N;i++){
        //                        cout<<*(allWord[i].getStr())<<"--------";
        //                        auto it=allWord[i].getList()->begin();
        //                        auto itInt=allWord[i].getNextLen()->begin();
        //                        for(;it!=allWord[i].getList()->end();){
        //                            cout<<*((*it)->getStr())<<" "<<(*itInt)<<" ";
        //                            it++;
        //                            itInt++;
        //                        }
        //                        cout<<endl;
        //                    }
    }

    //list<word*> *dragon_ofMaxLength;
    list<word*> BeginWord;
    list<int> BeginLength;
    //找到以beginChar开头的单词
    for(int i=0;i<N;i++){
        if(beginChar == allWord[i].getStr()->at(0))
        {
            BeginWord.push_back(allWord+i);
            BeginLength.push_back(allWord[i].getStr()->size());
        }
    }
    //长度知道了，下家也知道了，单词组失去意义了
    for(int i=0;i<N;i++) allWord[i].clearStr();

    creatDragon(&BeginWord,&BeginLength);
    cout<<MaxLength<<endl;
}