1.头文件HString.h

#pragma once

#include<iostream.h>
#include<assert.h>
#include<string.h>
#include<stdlib.h>

#define SIZE 255
typedef struct HString
{
	char *ch;
	int length;
}HString;

void Show();   //菜单显示
void InitHString(HString *T);//初始化
void StrAssign(HString *T, char *str);//初始化字符串
void PrintString(HString *T); //显示字符串
int Length(HString *S);  //求字符串长度
bool StrEmpty(HString *S);//判空
bool STrFull(HString *S);//判满
void StrCopy(HString *T, HString *S);//复制字符串
void DestroyString(HString *S);  //摧毁字符串
int StrDelete(HString *T, int pos, int len);  //按位置和长度删除字符串
void Replace(HString *T, HString *P, HString *V,int pos);//按位置替换字符串
int Index(HString *T, int pos, HString *P);//按位置匹配字符串
void StrInsert(HString *D, int pos, HString *T);//按位置插入字符串
int SubString(HString *D,HString *S, int pos, int len);//按位置获取字符串
void ClearString(HString *S);   //清理字符串
int StrCompare(HString *T, HString *S);//比较字符串
void StringConcat(HString *T, HString *s1,HString *s2);//链接字符串

2.功能模块HString.cpp

#include"HString.h"

void Show()
{
	cout<<"*********************************************"<<endl;
	cout<<"*[1]:  初始化字符串        [2]:拷贝字符串   *"<<endl;
	cout<<"*[3]:  比较字符串          [4]:求字符串长度 *"<<endl;
	cout<<"*[5]:  显示字符串          [6]:清理字符串   *"<<endl;
	cout<<"*[7]:  链接字符串          [8]:按位置得子串 *"<<endl;
	cout<<"*[9]:  匹配字符串          [10]:替换字符串  *"<<endl;
	cout<<"*[11]: 插入字符串          [12]:按位删除    *"<<endl;
	cout<<"*[13]: 摧毁字符串          [0]:结束程序     *"<<endl;
	cout<<"*********************************************"<<endl;
	cout<<"请选择：";
}
int StrDelete(HString *T, int pos, int len)
{
	if((pos+len)>T->length)
		return -1;
	char *ret=T->ch;
	int i=0;
	while(i<len)//abcdefg
	{
		ret[pos+i]=ret[i+pos+len];
		i++;
	}
	return 1;
}
void StrInsert(HString *D, int pos, HString *T)
{
	if(pos<0)
		return;
	char *ret=D->ch;
	for(int i=D->length;i>pos;i--)
	{
		ret[i+T->length]=ret[i];
	}
	while(pos--)
	{
		ret++;
	}

	while(*T->ch!='\0')
	{
		*ret++=*T->ch++;
	}
}

void Replace(HString *T, HString *P, HString *V,int pos)//按位置替换字符串,用V字符串去替换
{
	int wei=Index(T,pos,P);
	if(wei==-1)
	{
		cout<<"没有找到合适的替换位置"<<endl;
		return;
	}
	char *ret=T->ch;
	while(*V->ch!='\0')
	{
		*ret++=*V->ch++;
	}
}

int Index(HString *T, int pos, HString *P)//按位置匹配，P是子串T是父串
{
	if(pos+P->length>T->length)
		return -1;
	int count=pos;
	while(count--)
	{
		T->ch++;
	}
	char *ret=T->ch;
	char *p=P->ch;
	int t_size=pos;
	int length=T->length-P->length;
	while(*p!='\0' && length>=P->length)
	{
		if(*ret==*p)
		{
			ret++;
			p++;
		}
		else
		{
			p=P->ch;
			ret=++T->ch;
			t_size++;
			length--;
		}
	}
	if(length<P->length)
		return -1;
	else
		return t_size;
}

int SubString(HString *D,HString *S, int pos, int len)
{
	if(pos+len>S->length)
		return -1;
	int i=0;
	while(i++<pos)
	{
		S->ch++;
	}
	char *ret=S->ch;
	char *t=D->ch;
	while(len--)
	{
		*t++=*ret++;
	}
	*t='\0';
	return 1;
}
void StringConcat(HString *T, HString *s1,HString *s2)
{
	if(((s1->length)+(s2->length))>SIZE)
		return;
	char *ret=T->ch;
	while(*s1->ch!='\0')
	{
		*ret++=*s1->ch++;
	}
	while(*s2->ch!='\0')
	{
		*ret++=*s2->ch++;
	}
	*ret=*s2->ch;
}
void DestroyString(HString *S)
{
	free(S->ch);
	S->ch=NULL;
	S->length=0;
}
void ClearString(HString *S)
{
	*S->ch='\0';
	S->length=0;
}
int Length(HString *S)
{
	return S->length;
}
int StrCompare(HString *T, HString *S)
{
	while(*T->ch==*S->ch)
	{
		T->ch++;
		S->ch++;
	}
	if(*T->ch>*S->ch)
		return 1;
	else if(*T->ch<*S->ch)
		return -1;
	else
		return 0;
}

void StrCopy(HString *T, HString *S)
{
	if(STrFull(T))
	{
		cout<<"空间已满"<<endl;
		return;
	}
	char *p=T->ch;
	while(*S->ch!='\0')
	{
		*p++=*S->ch++;
	}
	*p=*S->ch;
}

void InitHString(HString *T)
{
	T->ch=(char*)malloc(sizeof(char)*SIZE);
	if(T->ch==NULL)
	{
		cout<<"开辟内存失败"<<endl;
		return;
	}
	T->length=0;
}

bool StrEmpty(HString *S)
{
	return S->length==0;
}
bool STrFull(HString *S)
{
	return S->length>=SIZE;
}
void StrAssign(HString *T, char *str)
{
	if(STrFull(T))
	{
		cout<<"内存已满"<<endl;
		return;
	}
	char *Str=T->ch;

	while(*str!='\0')
	{
		*Str++=*str++;
		T->length++;
	}
	*Str=*str;
}

void PrintString(HString *T)
{
	char *str=T->ch;
	while(*str!='\0')
	{
		cout<<*str;
		str++;
	}
	cout<<endl;
}

3.主函数main.cpp

#include"HString.h"

void main()
{
	char *str="abcdefg";
	char *ret="xy";
	char *p="ggg";

	HString S;
	HString TS;
	HString RS;

	InitHString(&S);
	InitHString(&TS);
	InitHString(&RS);
	int pos=1;
	int length=0;
	while(pos)
	{
		Show();
		cin>>pos;
		switch(pos)
		{
		case 1:
			StrAssign(&S,str);
			StrAssign(&TS,ret);
			break;
		case 2:
			StrCopy(&TS,&S);
			cout<<"拷贝后的字符串：";
			PrintString(&TS);
			break;
		case 3:
			pos=StrCompare(&S,&TS);
			cout<<"比较后的值："<<pos<<endl;
			break;
		case 4:
			cout<<"字符串长度："<<Length(&S)<<endl;
			break;
		case 5:
			PrintString(&S);
			break;
		case 6:
			ClearString(&S);
			break;
		case 7:
			StringConcat(&RS,&S,&TS);
			cout<<"链接后的字符串："<<RS.ch<<endl;
			break;
		case 8:
			StrAssign(&S,str);
			cout<<"请输入位置：";
			cin>>pos;
			cout<<"输入长度：";
			cin>>length;
			pos=SubString(&RS,&S,pos,length);
			if(pos!=-1)
			    cout<<"子串："<<RS.ch<<endl;
			else
				cout<<"输入位置和长度不合理"<<endl;
			break;
		case 9:
			StrAssign(&S,str);
			StrAssign(&TS,ret);
			cout<<"输入位置：";
			cin>>pos;
			pos=Index(&S,pos,&TS);
			if(pos!=-1)
				cout<<"在"<<pos<<"位置匹配成功"<<endl;
			else
				cout<<"匹配不成功"<<endl;
			break;
		case 10:
			StrAssign(&S,str);
			StrAssign(&TS,ret);
			StrAssign(&RS,p);
			cout<<"输入位置：";
			cin>>pos;
			Replace(&S,&TS,&RS,pos);
			cout<<S.ch<<endl;
			break;
		case 11:
			StrAssign(&S,str);
			StrAssign(&TS,ret);
			cout<<"输入位置：";
			cin>>pos;
			StrInsert(&S,pos,&TS);
			cout<<S.ch<<endl;
			break;
		case 12:
			StrAssign(&S,str);
			cout<<"请输入位置：";
			cin>>pos;
			cout<<"输入长度：";
			cin>>length;
			pos=StrDelete(&S,pos,length);
			if(pos!=-1)
				cout<<S.ch<<endl;
			else
				cout<<"位置或长度不合适，不能完成删除"<<endl;
			break;
		case 13:
			DestroyString(&S);
			cout<<"字符串已被摧毁"<<endl;
			break;
	//	case 0:  exit(-1);
		default:
				break;
		}
	}
}