考研系列二-线性表合并

套用系列一的线性表类，又加了三个成员函数：

#include <fstream>
#include <iostream>
#include <cstring>
#include <cstdlib>

using namespace std;

#define N 100
enum Status{success,fail,fatal,range_error,overflow};

class List{
    private:
    char *list;
    int len;

    public:
    List(char *tlist=""){
        list=new char[N];
        strcpy(list,tlist);//初始化
        len=strlen(list);
    }
    ~List(){
        delete list;
    }
    void listClear(){//销毁
        list[0]='';
        len=0;
    }
    bool listEmpty(){//判空
        return len==0;
    }
    int listSize(){//求长度
        return len;
    }
    Status listRetrieve(int pos,char &elem){//取指定位置元素
        if(pos>=0&&pos<len){
            elem=list[pos];
            return success;
        }else   return range_error;
    }
    Status listLocate(char elem,int &pos);//按值查找
    Status listInsert(int pos,char elem);//插入
    Status listRemove(int pos);//删除
    Status listPrior(int pos,char &elem);//求前驱
    Status listNext(int pos,char &elem);//求后继
    void listShow();//显示表内容
    Status listUnion(List &list2);//集合合并
    Status listMerge(List &list1,List &list2);//有序表合并
};

int main(){
    //freopen("D:\input.in","r",stdin);
    //freopen("D:\output.out","w",stdout);
    List s1("hello"),s2("echo"),s10("abcdegkl"),s11("bdefhk"),s12;

    s1.listShow();
    if(s1.listUnion(s2)==success)   s1.listShow();

    s10.listShow();
    s11.listShow();
    if(s12.listMerge(s10,s11)==success)     s12.listShow();
    return 0;
}
Status List::listLocate(char elem,int &pos){
    for(int i=0;i<len;i++){
        if(list[i]==elem){
            pos=i;
            return success;
        }
    }
    return fail;
}
Status List::listInsert(int pos,char elem){
    if(len==N-1)     return overflow;//因为终止符
    if(pos<0||pos>len)  return range_error;
    for(int i=len+1;i>pos;i--)    list[i]=list[i-1];
    list[pos]=elem;
    len++;
    return success;
}
Status List::listRemove(int pos){
    if(pos<0||pos>=len)  return range_error;
    for(int i=pos;i<len-1;i++)    list[i]=list[i+1];
    len--;
    return success;
}
Status List::listPrior(int pos,char &elem){
    return listRetrieve(pos-1,elem);
}
Status List::listNext(int pos,char &elem){
    return listRetrieve(pos+1,elem);
}
void List::listShow(){
    puts(list);
}
Status List::listUnion(List &list2){
    char elem;
    Status status;
    int pos,len2=list2.listSize();
    for(int i=0;i<len2;i++){
        list2.listRetrieve(i,elem);
        status=listLocate(elem,pos);
        if(status!=success){
            status=listInsert(len,elem);
            if(status!=success) break;
        }
    }
    return status;
}
Status List::listMerge(List &list1,List &list2){
    char elem1,elem2;
    int len1,len2,i=0,j=0;
    Status status;
    len1=list1.listSize();
    len2=list2.listSize();
    while(i<len1&&j<len2){
        list1.listRetrieve(i,elem1);
        list2.listRetrieve(j,elem2);
        if(elem1<elem2){
            status=listInsert(len,elem1);
            i++;
        }else{
            status=listInsert(len,elem2);
            j++;
        }
        if(status!=success) return status;
    }
    while(i<len1){
        list1.listRetrieve(i,elem1);
        listInsert(len,elem1);
        if(status!=success) return status;
        i++;
    }
    while(j<len2){
        list2.listRetrieve(j,elem2);
        status=listInsert(len,elem2);
        if(status!=success) return status;
        j++;
    }
    return status;
}

敲代码期间遇到一个bug，就是字符串的终止符问题，合并时不小心把终止符给覆盖了，结果程序就飞了。