/************ stack.h ************/
#include<vector>
#include<iostream>
#include<algorithm>
using namespace std;
class stack
{
    public:
    bool find(const string &elem) const;
    int count(const string &elem) const;
...
...
    private:
    vector<string> _stack;

};

/********** stack.cpp **********/

#include "stack.h"
...
...
bool stack::find (const string &elem) const
{
    vector<string>::const_iterator it = _stack.begin();
    return (::find(it,_stack.end(),elem))!=_stack.end();
}
int stack::count(const string &elem) const
{

    return (::count(_stack.begin(),_stack.end(),elem));
}

/*********** main.cpp *************/
#include "stack.cpp"
#include<fstream>
int main()
{
    stack st;
    string str;
    ifstream readfile("sentence.txt");
    while(readfile>>str && !st.full())
    {
        st.push(str);
    }
...
    cout<<"\nEnter a word to search: ";
    cin>>str;
    if(st.find(str))
        cout<<"The word was found "<<st.count(str)<<" no. of times"<<endl;
    else
        cout<<"The word was not found"<<endl;
    return 0;

}