Number of small strings in C + + statistics string

Problem:
How to find the number of small strings in a string.
For example, find the number of ' B ' in the string "ABCADFBCAEBF" or the number of "Ca"
===================================================================================
Writing a:
int Substr (CString str,cstring sub)
{
int nret= 0, nstart = 0;
while ( -1!= (NSTART=STR). Find (Sub,nstart))
{
Nstart+=sub. GetLength ();
++nret;
}
return nret;
}


Usage
int N=substr ("ABCADFBCAEBF", "B");
int N=substr ("ABCADFBCAEBF", "Ca");

==================================================================
Another way of writing:

CString str;
str = "ABCADFBCAEBF";
int ncount1=0, ncount2=0;
for (int i=0; I <str.   GetLength (); i++)
{
if (str[i] = = ' B ')
ncount1++;
}
while (!str. IsEmpty ())
{
int index;
if (index = str. Find ("Ca"))!=-1)
{
ncount2++;
str = str. Mid (index+2);
}
Else
Break
}
============================================================================================
Using a hash table, map:http://wenwen.soso.com/z/q278570518.htm

#pragma warning (disable:4786)
#include <iostream>
#include <map>
#include <algorithm>
using namespace Std;
typedef map<char,int> MAP;
void print (Map::value_type t)
{
cout<<t.first<< ": Have" <<t.second<< "a" <<endl;
}
void Countcharacter (MAP &m,char *sztext)
{
Char *p=sztext;
if (!p)
Return
while (*P)
{
Map::iterator It=null;
It=m.find (*P);
if (It==m.end ())
{
M.insert (Map::value_type (*p,1));
}
Else
{
+ + (It->second);
}
++p;
}
Return
}
int main ()
{
MAP Mymap;
Char sztext[512]={0};
cout<< "Please enter a string:" <<endl;
Fgets (Sztext,512,stdin);
Sztext[strlen (Sztext) -1]=0;
Countcharacter (Mymap,sztext);
For_each (Mymap.begin (), Mymap.end (), print);
return 0;
}