How to delete a specific character and sort all the value and delete duplicate value from a string ? in c++

#include<bits/stdc++.h>
using namespace std;
int main()
{
    string s;
    s.erase(remove(s.begin(),s.end(), ' '),s.end());
    sort(s.begin(), s.end());
    s.erase(unique(s.begin(), s.end()), s.end());

    cout<<s<<endl;

return 0;
}