统计在一个文本框内个英文字母出现的次数

#include <iostream>
#include <string>
#include <map>
#include <vector>

using namespace std;

string toupperstr(string a)
{
string b(a);
int asize = a.size();
for ( size_t i = 0; i < asize; ++i )
b[i] = toupper(int (b[i]));
return b;
}

void CharCount(vector<string> &sv)
{
map<string,int> result;
vector<string>::const_iterator ib = sv.begin(), ie = sv.end();
for ( ; ib != ie; ++ib )
{
string t = toupperstr(*ib);
if ( result.find(t) != result.end() )
++result[t];
else
result.insert(make_pair(t,1));
}

for ( ib = sv.begin(); ib != ie; ++ib )
{
cout << *ib << " take " << result[toupperstr(*ib)] << " times\n";
}
}

int main()
{
vector<string> sv;
for ( int i = 0; i < 10;