Z Function Algorithm

Siegel Z-function, the Riemann – Siegel zeta-function, the Hardy function, the Hardy Z-function and the Hardy zeta-function. It follows from the fact that the Riemann-Siegel theta-function and the Riemann zeta-function are both holomorphic in the critical strip, where the imaginary part of t is between −1/2 and 1/2, that the Z-function is holomorphic in the critical strip also.
/*************************************************************************************

    Z function. O(N)

    About it: http://e-maxx.ru/algo/z_function
    Based on problem 1324 from informatics.mccme.ru:
    http://informatics.mccme.ru/mod/statements/view3.php?id=241&chapterid=1324

*************************************************************************************/

#include <iostream>
#include <fstream>
#include <cmath>
#include <algorithm>
#include <vector>
#include <set>
#include <map>
#include <stack>
#include <queue>
#include <cstdlib>
#include <cstdio>
#include <string>
#include <cstring>
#include <cassert>
#include <utility>
#include <iomanip>

using namespace std;

const int MAXN = 1000100;

string s;
int n;
int z[MAXN];
int l, r;

int main() {
    //assert(freopen("input.txt","r",stdin));
    //assert(freopen("output.txt","w",stdout));

    getline(cin, s);
    n = (int) s.length();

    l = r = 0;
    for (int i = 2; i <= n; i++) {
        int cur = 0;
        if (i <= r)
            cur = min(r - i + 1, z[i - l + 1]);
        while (i + cur <= n && s[i + cur - 1] == s[cur])
            cur++;
        if (i + cur - 1 > r) {
            l = i; r = i + cur - 1;
        }
        z[i] = cur;
    }

    z[1] = n;
    for (int i = 1; i <= n; i++)
        printf("%d ", z[i]);

    return 0;
}

LANGUAGE:

DARK MODE: