data_structs.rar_Data structs_structs

#include<iostream.h> #include<stdlib.h> #include<string.h> #include"stringclass.h" String::String(const char *c)//缺省构造函数的实现 { size=strlen(c); str=new char[size+1]; if(str==NULL) Error("String:overflow!"); strcpy(str,c); } String::String(const String& cs)//拷贝构造函数的实现 { size=cs.size; str=new char[size+1]; if(str==NULL) Error("String:overflow!"); strcpy(str,cs.str); } //类串的输入输出 istream& operator>>(istream& istr,String& cs) { char tmp[256]; istr>>tmp; cs=tmp; return(istr); } ostream& operator<<(ostream& ostr,const String& cs) { ostr<<cs.str; return(ostr); } int String::ReadString(istream& istr,char delimiter) { char tmp[256]; if(istr.getline(tmp,256,delimiter)) { *this=tmp; return(size); } else return(-1); } //赋值运算符 String& String::operator=(const String& cs)//类串=类串 { if(size!=cs.size) { delete[]str; size=cs.size; str=new char[size+1]; if(str==NULL) Error("operator=:overflow!"); } strcpy(str,cs.str); return(*this); } String& String::operator=(const char *c) //类串=C串 { int n=strlen(c); if(size!=n) { delete[]str; size=n; str=new char[size+1]; if(str==NULL) Error("operator=:overflow!"); } strcpy(str,c); return(*this); } //成员转换函数 String::operator char*(void)const { return(str); } //串连接运算符 String String::operator+(const String& cs)const { String w; delete[]w.str; w.size=size+cs.size; w.str=new char[w.size+1]; if(w.str==NULL) Error("operator+:overflow!"); strcpy(w.str,str); strcat(w.str,cs.str); return(w); } String String::operator+(const char *c)const//String+C++String { String w; delete[]w.str; w.size=size+strlen(c); w.str=new char[w.size+1]; if(w.str==NULL) Error("operator+:overflow!"); strcpy(w.str,str); strcat(w.str,c); return(w); } String operator+(const char *c,const String& cs)//C++String+String { String w;//不能简化为return(cs+c),因为连接后的串顺序不对 delete[]w.str; w.size=strlen(c)+cs.size; w.str=new char[w.size+1]; if(w.str==NULL) //友元不能调用私有函数Error { cerr<<"operator+:overflow!"; exit(1); } strcpy(w.str,c); strcat(w.str,cs.str); return(w); } String& String::operator+=(const String& cs)//String+String { char *tmp=new char[size+1]; if(tmp==NULL) Error("operator+=:overflow!"); strcpy(tmp,str); delete[]str; size=size+cs.size; str=new char[size+1]; if(str==NULL) Error("operator+=:overflow!"); strcpy(str,tmp); strcat(str,cs.str); delete tmp; return(*this); } String& String::operator+=(const char *c) { char *tmp=new char[size+1]; if(tmp==NULL) Error("operator+=:overflow!"); strcpy(tmp,str); delete[]str; size=size+strlen(c); str=new char[size+1]; if(str==NULL) Error("operator+=:overflow!"); strcpy(str,tmp); strcat(str,c); delete tmp; return(*this); } String String::SubString(int id,int count)const { String cs; if(id<0) Error("SubString:id illegal!"); if(id>size-1||count<=0) count=0; int left=size-id; if(left>0&&count>left) count=left; delete[]cs.str; cs.size=count; cs.str=new char[cs.size+1]; if(cs.str==NULL) Error("SubString:overflow!"); char* p=cs.str; char* q=str+id; for(int i=1;i<=count;i++) *p++=*q++; *p='\0'; return(cs); } String& String::Insert(const char *c,int id) { if(id<0||id>size) Error("Insert:id illegal!"); char* temp=new char[size+1]; if(temp==NULL) Error("Insert:overflow!"); strcpy(temp,str); delete[]str; int n=size+strlen(c); //新串长 str=new char[n+1]; if(str==NULL) Error("Insert:overflow!"); strcpy(str,temp); delete[]temp; char* p=str+size; char* q=str+n; int left=size-id+1; //包括串结束符 for(int i=1;i<=left;i++) *q--=*p--; p=str+id; i=0; while(*(c+i)!='\0')//c是const指针 *p++=*(c+i++); size=n; return(*this); } String& String::Insert(const String& cs,int id) { if(id<0||id>size) Error("Insert:id illegal!"); char* temp=new char[size+1]; if(temp==NULL) Error("Insert:overflow!"); strcpy(temp,str); delete[]str; int n=size+cs.size; str=new char[n+1]; if(str==NULL) Error("Insert:overflow!"); strcpy(str,temp); delete[]temp; char* p=str+size; char* q=str+n; int left=size-id+1; //需要移动的字符数，包括串结束符 for(int i=1;i<=left;i++) *q--=*p--; p=str+id; q=cs.str; while(*q!='\0') *p++=*q++; size=n; return (*this); } void String::Erase(int id,int count) { if(id>size-1||count<=0) return; if(id<0) Error("Delete:id illegal!"); int left=size-id; if(count>left) count=left; char* p=str+id; char* q=str+id+count; while(*q!='\0') *p++=*q++; *p='\0'; size=strlen(str); char* tmp=new char[size+1]; if(tmp==NULL) Error("Delete :overflow!"); strcpy(tmp,str); delete[]str; str=new char[size+1]; if(str==NULL) Error("Delete :overflow!"); strcpy(str,tmp); delete[]tmp; } char& String::operator[](int id) { if(id<0||id>size-1) Error("operator[]:Id illegal!"); return(*(str+id)); //return(str[id]); } const char& String::operator[](int id)const { if(id<0||id>size-1) Error("operator[]:Id illegal!"); return(*(str+id)); //return(str[id]); } int String::Find(char ch,int start)const { int i; char *p; if(start>size-1) return(-1); if(start<0) start=0; for(p=str+start,i=start;*p!='\0';++p,++i) if(*p==ch) return(i); return(-1); } int String::FindLast(char ch)const { int i; char *p; for(p=str+size-1,i=size-1;p!=str;--p,--i) if(*p==ch) return(i); return(-1); }