Minimal rotations required to delete each Strings

#embody <bits/stdc++.h>

utilizing namespace std;

string leftrotate(string& s, int d)

{

    reverse(s.start(), s.start() + d);

    reverse(s.start() + d, s.finish());

    reverse(s.start(), s.finish());

    return s;

}

int MinimumRotations(string A, string B)

{

    int rotations = 0;

    int len = A.size();

    int B_index = 0;

    for (int i = 0; i < len; i++) {

        if (A[0] == B[B_index]) {

            A.erase(A.start() + 0);

            B_index++;

        }

        if (A[0] != B[B_index]) {

            A = leftrotate(A, 1);

            rotations++;

            i = 0;

        }

    }

    return rotations;

}

int fundamental()

{

    string A = "geek";

    string B = "geek";

    cout << MinimumRotations(A, B) << endl;

    string A2 = "abcd";

    string B2 = "bcda";

    cout << MinimumRotations(A2, B2) << endl;

    string A3 = "agef";

    string B3 = "afge";

    cout << MinimumRotations(A3, B3) << endl;

    return 0;

}