KMP Algorithm

/**------------------------
    Author : NikolaP
    Compiler : C++
-------------------------*/

//{         Setup

    #include <bits/stdc++.h>
    using namespace std;

    typedef long long int ll;
    typedef long double ld;
    typedef vector<int> vi;

    const int inf = INT_MAX;
    const bool debug = 0;

//}

struct KMP{
    string text, pattern;
    vi key;

    void process(){
        int len = pattern.size();
        key.assign(len+1,0);

        int i = 0, j = -1;
        key[0] = -1;

        while(i < len){
            while(j >= 0 and pattern[i] != pattern[j]) j = key[j];
            i++; j++;
            key[i] = j;
        }
    }

    KMP(string _text, string _pattern){
        text = _text;
        pattern = _pattern;
        process();
    }

    void Solution(){
        int i = 0, j = 0;
        while(i < text.size()){
            while(j >= 0 and text[i] != pattern[j]) j = key[j];
            i++; j++;
            if(j == pattern.size()){
                cout << "Index: " << i-j << '\n';
                j = key[j];
            }
        }
    }
};


int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.precision(8);
    //cout << fixed;

    string a,b;
    getline(cin,a);
    getline(cin,b);

    KMP kmp = KMP(a,b);
    kmp.Solution();
    return 0;
}