XAUDX C++

#include<bits/stdc++.h>
using namespace std;
string s;
int n,d,res[10000000],len;

void xuat()
{
    cout << d << endl;
    for(int i=1;i<=d;i++)
    {
        cout << res[i] << " ";
        if(i%20==0) cout << endl;
    }
}
bool dx(string s)
{
    len=s.length();
    for(int i=0;i<len/2;i++)
    {
        if(s[i]!=s[len-i-1]) return false;
    }
    return true;
}
int main()
{
    //freopen("XAUDX.inp","r",stdin);
    //freopen("XAUDX.out","w",stdout);
    cin >> n;
    d=0;
    for(int i=1;i<=n;i++)
    {
        cin >> s;
        if(dx(s)==true)
        {
            d++;
            res[d]=i;
        }
    }
    xuat();
}