2107 - String Functions.cpp

/*
Problem Name: String Functions
Problem Link: https://cses.fi/problemset/task/2107
Author: Sachin Srivastava (mrsac7)
*/
#include<bits/stdc++.h>
using namespace std;
 
#define int long long
#define endl '\n'
 
const int mxN = 1e6+6;
int pi[mxN], z[mxN];
 
signed main(){
    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    #ifdef LOCAL
    freopen("input.txt", "r" , stdin);
    freopen("output.txt", "w", stdout);
    #endif
    
    string s; cin>>s;
    int n = s.size();

    for (int i = 1, l = 0, r = 0; i < n; i++) {
        int j = pi[i-1];
        while (j && s[j] != s[i])
            j = pi[j-1];
        if (s[j] == s[i])
            j++;
        pi[i] = j;

        z[i] = max(0LL, min(z[i - l], r - i + 1));
        while (i + z[i] < n && s[z[i]] == s[i + z[i]]) 
            z[i]++;
        if (i + z[i] - 1 > r)
            l = i, r = i + z[i] - 1;
    }

    for (int i = 0; i < n; i++)
        cout << z[i] << ' ';
    cout << endl;
    for (int i = 0; i < n; i++)
        cout << pi[i] << ' ';
}