b6_8.cxx

b6_8.cxx

#include ‹stream.hxx›

#include ‹string.h›

struct pair {

 char* name;

 int val;

};

class assoc {

 friend class assoc_iterator;

 pair* vec;

 int max;

 int free;

public:

 assoc(int);

 int& operator[](char*);

};

class assoc_iterator {

 assoc* cs;

 int i;

public:

 assoc_iterator(assoc& s) { cs =&s; i = 0; }

 pair* operator()()

 { return (i‹cs-›free) ? &cs-›vec[i++] : 0; }

};

assoc::assoc(int s)

{

 max = (s‹16) ? s : 16;

 free = 0;

 vec = new pair[max];

}

int& assoc::operator[](char* p)

{

 register pair* pp;

 for (pp = &vec[free-1]; vec‹=pp; pp--)

  if (strcmp(p,pp-›name)==0) return pp-›val;

 if (free == max) {

  pair* nvec = new pair[max*2];

  for (int i=0; i‹max; i++) nvec[i] = vec[i];

  delete vec;

  vec = nvec;

  max = 2*max;

 }

 pp =&vec[free++];

 pp-›name = new char[strlen(p)+1];

 strcpy(pp-›name,p);

 pp-›val = 0;

 return pp-›val;

}

main()

{

 const MAX = 256;

 char buf[MAX];

 assoc vec(512);

 while (cin››buf) vec[buf]++;

 assoc_iterator next(vec);

 pair* p;

 while (p = next())

  cout ‹‹ p-›name ‹‹ ": " ‹‹ p-›val ‹‹ " ";

}