String Transformation

#include <iostream>
#include <string>
#include <algorithm>
using namespace std;
string a, b, s1, s2;
int main()
{
    getline(cin, a);
    getline(cin, b);
    if (a.length() != b.length())
    {
        cout << "-1 -1";
        return 0;
    }
    int n = a.length();
    s1 = a; reverse(s1.begin(),s1.end()); s1 += '\0' + b;
    s2 = b + '\0' + a;
    int *p = new int[2 * n + 1];
    p[0] = 0;
    for (int i = 1; i < 2 * n + 1; ++i)
    {
        p[i] = p[i - 1];
        while (p[i] > 0 && s1[p[i]] != s1[i])
            p[i] = p[p[i] - 1];
        if (s1[p[i]] == s1[i])
            ++p[i];
    }
    int *z = new int[2 * n + 1];
    z[0] = 0;
    for (int i = 1, l = 0, r = 0; i < 2 * n + 1; ++i)
    {
        z[i] = 0;
        if (i <= r)
            z[i] = min(z[i - l], r - i + 1);
        while (i + z[i] < 2 * n + 1 && s2[z[i]] == s2[i + z[i]])
            ++z[i];
        if (i + z[i] - 1 > r)
        {
            l = i;
            r = i + z[i] - 1;
        }
    }
    int ans_i = -1, ans_j = -1;
    for (int i = 0; i < n - 1; ++i)
    {
        if (a[i] != b[n - i - 1]) break;
        int len = p[2 * n - i - 1];
        if (z[n + i + 2] >= n - i - len - 1)
        {
            ans_i = i;
            ans_j = n - len;
        }
    }
    cout << ans_i << ' ' << ans_j << endl;
    return 0;
}