z_algorithm( Brute Force/ Trivial algorithm )

z_algorithm(Brute Force).cpp

void z_algo(string s){
    int n = (int) s.length();
    vector<int> z(n);
    z[0] = 0; // z[0] = 0 or z[0] = n according to problem statement;
    for(int i=1; i<n; ++i){
        while (i + z[i] < n && s[z[i]] == s[i + z[i]]){
            ++z[i];
        }
    }
}