searchkey.cpp

该程序实现了用文件记录变长字节流

#include<iostream.h>
#include<fstream.h>
#include<stdlib.h>
#include<iomanip.h>
#include<string.h>
#include"index.h"
index searchkey(char *p,index &a)
{fstream f1(p,ios::in|ios::out|ios::binary);
if(!f1)
{cerr<<"exit error!"<<endl;
exit(1);
}
index c={-1,"nulltag",2};
f1.seekg(0,ios::end);
int total=f1.tellg()/d1;
index *A=new index[total];
f1.seekg(0,ios::beg);
f1.read((char *)A,total*d1);
for(int i=0;i<total;i++)
{if(A[i].key==a.key&&A[i].deletetag==0)
c=A[i];
if(A[i].key>a.key)
break;
}
if(c.key==-1) cout<<"not such element!"<<endl;
else cout<<c.key<<c.name<<endl;
return c;
}