Z_Function.cpp

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

// Longest prefix start at index i that match with string s, O(n)
vector<int> z_function(const string &s) {
    int n = s.size();
    vector<int> z(n);
    int l = 0, r = 0;
    for (int i = 1; i < n; i++) {
        if (i < r) {
            z[i] = min(r - i, z[i - l]);
        }
        while (i + z[i] < n && s[z[i]] == s[i + z[i]]) {
            z[i]++;
        }
        if (i + z[i] > r) {
            l = i;
            r = i + z[i];
        }
    }
    return z;
}

void solve() {
    string s;
    cin >> s;

    int n = s.size();
    vector<int> z = z_function(s);
    for (int i = 0; i < n; i++) {
        cout << z[i] << " \n"[i == n - 1];
    }
}

int32_t main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int t = 1;
    //cin >> t;

    while (t--) {
        solve();
    }

    return 0;
}