练习5.9 自引用
、
程序代码如下：
View Code #include <iostream> using namespace std; enum Context{ c_comment,cpp_comment,string_literal,char_literal,file_end }; void handle_c_comment(){ char ch; while(cin. get(ch)){ if(ch== ' * '){ while(cin. get(ch)&&ch== ' * ') ; if(ch== ' / ') break; } } } void handle_cpp_comment(){ char ch; while(cin. get(ch)&&ch!= ' \n ') ; } void handle_literal( char delimiter){ cout<<delimiter; char ch; while(cin. get(ch)){ cout<<ch; if(ch==delimiter) break; else if (ch== ' \\ ') cin. get(ch)&&cout<<ch; } } Context handle_code(){ char ch; while(cin. get(ch)){ switch(ch){ case ' / ': if(!cin. get(ch)){ cout<< ' / '; return file_end; } else { if(ch== ' * ') return c_comment; else if(ch== ' / ') return cpp_comment; else{ cout<< ' / '; cin.putback(ch); break; } } case ' \" ': return string_literal; case ' \' ': return char_literal; default: cout<<ch; } } return file_end; } int main( int argc, char**argv){ if(argc!= 1){ cerr<< " This program takes no arguments.\n "; return - 1; } else{ Context contxt; while((contxt=handle_code())!=file_end) switch(contxt){ case c_comment: handle_c_comment(); break; case cpp_comment: handle_cpp_comment(); break; case string_literal: handle_literal( ' \" '); break; case char_literal: handle_literal( ' \' '); break; } } return 0; }
代码如下：
View Code #include <iostream> #include <typeinfo> using namespace std; #define CTOR(CC){ \ cout<<#CC " Constructor: " \ <<typeid(* this).name()<< ' \n ';\ from_outside( this);\ cout<< ' \n ';\ } #define DTOR(CC){ \ cout<<#CC " destructor: "\ <<typeid(* this).name()<< ' \n ';\ from_outside( this);\ cout<< ' \n ';\ } struct A; void from_outside(A * object); struct A{ A() CTOR(A) ~A() DTOR(A) }; void from_outside(A * object){ cout<< " Located at address: "<<( void*) object << " \nFrom outside: "<<typeid(* object).name() <<endl; } struct B; void from_outside(B * object); struct B: A{ B() CTOR(B) virtual ~B() DTOR(B) }; void from_outside(B * object){ cout<< " Located at address: "<<( void*) object << " \nFrom outside: "<<typeid(* object).name() <<endl; } struct C: B{ C() CTOR(C) virtual ~C() DTOR(C) }; struct D: B{ D() CTOR(D) virtual ~D() DTOR(D) }; struct E; void from_outside(E* object); struct E: C,D{ E() CTOR(E) virtual ~E() DTOR(E) }; void from_outside(E* object){ from_outside((C*) object); from_outside((D*) object); } struct F: virtual B{ F() CTOR(F) virtual ~F() DTOR(F) }; struct G: virtual B{ G() CTOR(G) virtual ~G() DTOR(G) }; struct H:F,G{ H() CTOR(H) virtual ~H() DTOR(H) }; struct I; void from_outside(I* object); struct I:E,H{ I() CTOR(I) virtual ~I() DTOR(I) }; void from_outside(I* object){ from_outside((C*) object); from_outside((D*) object); from_outside((H*) object); } int main(){ I complex_obect; cout << " Total size of I-object : "<< sizeof (I)<<endl; }
程序输出如下：
代码如下：
View Code #include <iostream> #include < string> #include <cctype> #include <ctime> #include <cstdio> using namespace std; bool read_string( string &s){ int const buffer_size= 100; char buffer[buffer_size+ 1]; int i= 0,c; while((c=cin. get())&&cin&&isspace(c)) ; while((c=cin. get())&&cin&&!isspace(c) &&i!=buffer_size){ buffer[i++]= char(c); } buffer[i]= ' \0 '; s.assign(buffer,i); if(cin){ cin.putback(c); if(!isspace(c)){ string remainder; read_string(remainder); s.append(remainder); } return true; } else return false; } bool read_string2( string& s){ int const buffer_size= 100; char buffer[buffer_size+ 1]; int i= 0,c; while((c=getc(stdin))!=EOF&&isspace(c)) ; while((c=getc(stdin))!=EOF&&!isspace(c) &&i!=buffer_size){ buffer[i++]= char(c); } buffer[i]= ' \0 '; s.assign(buffer,i); if(c!=EOF){ ungetc(c,stdin); if(!isspace(c)){ string remainder; read_string(remainder); s.append(remainder); } return true; } else return false; } int main(){ string word; int n= 0; bool not_eof; clock_t start=clock(); #if defined(SIMPLE) while(cin) { cin>>word; n++; } #elif defined(SIMPLE2) do{ not_eof=read_string(word); ++n; } while(not_eof); #else do{ not_eof=read_string2(word); ++n; } while(not_eof); #endif printf( " Read %d words in %f seconds.\n ",n,(clock()-start)* 1.0/CLOCKS_PER_SEC); return 0; }
