optimal page replacement algorithm

[simson1]

There must be a change in the code to get specified output.
pages are 1 2 3 4 2 5 3 4 2 6 7 8 7 9 7 8 2 5 4 9
``
#include<bits/stdc++.h>
using namespace std;
int main()
{
int f,p,j=0,x,pf=0,h=0,m,i,index,u;
vectoro;
std::vector::iterator it;

cout<<"Enter no of pages"<<endl;
cin>>p;
cout<<"Enter the reference string"<<endl;
for(i=0;i<p;i++)
{
    cin>>x;
    o.push_back(x);
}
cout<<"Enter no of frames"<<endl;
cin>>f;
vector<int>a(f,-1);
while(j<p)
{
    m=0;
    if(j<=f-1)
{
    x=o.at(j);
    a.at(j)=x;
    ++pf;
}
    else
{
        if(find(a.begin(), a.end(), o.at(j))!=a.end())
        {
            ++h;
        }
        else
    {
            for(i=0;i<f;i++)
        {
                if(find(o.begin()+j+1,o.end(),a.at(i))!=o.end())
            {
                it=find(o.begin()+j+1,o.end(),a.at(i));
                if(it-o.begin()>m)
                {
                        m=(it-o.begin());index=i;

                }
            }
            else
            {
                index=i;
                break;
            }
       }
            x=o.at(j);
        a.at(index)=x;
        ++pf;
    }
}
        for(i=0;i<f;i++)
    {
        cout<<a[i]<<" ";

    }
    cout<<endl;
    ++j;
}
cout<<"No of page faults happen "<<pf<<endl;
   cout<<"No of page hit happen "<<h;

}