人都要调麻了（悲

自认为码风还过得去

#include<cstdio>
#include<cstring>
#include<algorithm>
#define LL long long
using namespace std;

const int MAXN = 1000005;

LL ans;
char str[MAXN];

class Graph {
	private : 
	struct edge {
		int to, nex;
	}e[MAXN]; int idx;
	public : 
	int head[MAXN];
	inline void add(int u, int v) {
		e[++ idx].to = v;
		e[idx].nex = head[u];
		head[u] = idx;
	}
	inline edge operator [] (const int x) const {
		return e[x];
	}
}G;
namespace SAM {
	int idx, lst;
	struct node {
		int fath, sons[26];
		int len, cnt;
	}tr[MAXN << 1];
	inline void nwNode(int length) {
		tr[++ idx].len = length;
		tr[idx].cnt = 1;
		tr[idx].fath = -1;
		memset(tr[idx].sons, 0, sizeof(tr[idx].sons));
	}
	inline void Init() {
		idx = -1, lst = 0;
		nwNode(0);
	}
	inline void Insert(int c) {
		nwNode(tr[lst].len + 1);
		int p = lst, cur = idx;
		while (p != -1 && !tr[p].sons[c])
			tr[p].sons[c] = cur, p = tr[p].fath;
		if (p == -1)
			tr[cur].fath = 0;
		else {
			int q = tr[p].sons[c];
			if (tr[q].len == tr[p].len + 1)
				tr[cur].fath = q;
			else {
				nwNode(tr[p].len + 1);
				int nq = idx;
				memcpy(tr[nq].sons, tr[q].sons, sizeof(tr[q].sons));
				tr[nq].fath = tr[q].fath;
				tr[cur].fath = tr[q].fath = nq;
				while (p != -1 && tr[p].sons[c] == q)
					tr[p].sons[c] = nq, p = tr[p].fath;
			}
		} 
		lst = cur;
	}
	inline void Build(char s[]) {
		Init();
		int length = strlen(s);
		for (int i = 0; i < length; ++ i)
			Insert(s[i] - 'a');
	}
	inline void dfs (int u) {
		for (int i = G.head[u]; i; i = G[i].nex) {
			int v = G[i].to;
			dfs(v);
			tr[u].cnt += tr[v].cnt;
		}
		if (tr[u].cnt != 1)
			ans = max(ans, 1ll * tr[u].len * tr[u].cnt);
	}
	inline void Get_cnt() {
		for (int i = 1; i <= idx; ++ i)
			G.add(tr[i].fath, i);
		dfs(0);
	}
}

int main()
{
	scanf ("%s", str);
	SAM::Build(str);
	SAM::Get_cnt(); 
	return printf ("%lld\n", ans), 0;
}