counting characters from a string

[tdk93]

I'm trying to count occurences of each character in a string and find out the maximum frequency of any character present in a substring and save it

this shows the following error
"In instaniation of 'std::iteratpr_traits<char>":
'char' is not a class, struct or union type

p = 0;
// s is the string
for ( int io = 97; io < 97+26; io++){
size_t to = std::count(s[p],s[array[p+1]],static_cast<char>(io));
if ( ct < to)
ct = to;
}
cout << ct;
if(new_ct[0]<ct)
new_ct[0] = ct;

[vlad from moscow]

Before using any function you should read its description.