Submission #563437

#	Time	Username	Problem	Language	Result	Execution time	Memory
563437		zaneyu	Palindromes (APIO14_palindrome)	C++14	100 / 100	80 ms	73744 KiB

palindrome

/*input
www
*/
#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
//order_of_key #of elements less than x
// find_by_order kth element
typedef long long int ll;
 
#define ld long double
#define pii pair<int,int>
typedef tree<pii, null_type, less<pii>, rb_tree_tag, tree_order_statistics_node_update> indexed_set;
#define f first
#define s second
#define pb push_back
#define REP(i,n) for(int i=0;i<n;i++)
#define REP1(i,n) for(int i=1;i<=n;i++)
#define FILL(n,x) memset(n,x,sizeof(n))
#define ALL(_a) _a.begin(),_a.end()
#define sz(x) (int)x.size()
const ll maxn=2e5+5;
const ll maxlg=__lg(maxn)+2;
const ll INF64=4e18;
const int MOD=1e9+7;
const int INF=0x3f3f3f3f;
const ld PI=acos(-1);
const ld eps=1e-9;
#define lowb(x) x&(-x)
#define MNTO(x,y) x=min(x,(__typeof__(x))y)
#define MXTO(x,y) x=max(x,(__typeof__(x))y)
#define SORT_UNIQUE(c) (sort(c.begin(),c.end()), c.resize(distance(c.begin(),unique(c.begin(),c.end()))))
#define GET_POS(c,x) (lower_bound(c.begin(),c.end(),x)-c.begin())+1
template<typename T1,typename T2>
ostream& operator<<(ostream& out,pair<T1,T2> P){
    out<<P.f<<' '<<P.s;
    return out;
}
template<typename T>
ostream& operator<<(ostream& out,vector<T> V){
    REP(i,sz(V)) out<<V[i]<<((i!=sz(V)-1)?"\n":"");
    return out;
}
ll mult(ll a,ll b){
    if(a<0) a+=MOD;
    return (a*b)%MOD;
}
ll mypow(ll a,ll b){
    if(b<=0) return 1;
    ll res=1LL;
    while(b){
        if(b&1) res=mult(res,a);
        a=mult(a,a);
        b>>=1;
    }
    return res;
}
struct Node {
    int nxt[26], sufflink;
    ll len, cnt;
    vector<int> edges;
} tree1[303030];

string s;
int suff, num;

void add_letter(int pos) {
    int curr = suff, curr_len = 0;
    int letter = s[pos] - 'a';

    while (true) {
        curr_len = tree1[curr].len;
        if (pos - 1 - curr_len > -1 && s[pos - 1 - curr_len] == s[pos])
            break;
        curr = tree1[curr].sufflink;
    }
    if (tree1[curr].nxt[letter]) {
        suff = tree1[curr].nxt[letter];
        tree1[suff].cnt++;
        return;
    }

    suff = ++num;
    tree1[num].len = tree1[curr].len + 2;
    tree1[num].cnt = 1;
    tree1[curr].nxt[letter] = num;

    if (tree1[num].len == 1) {
        tree1[num].sufflink = 2;
        tree1[2].edges.push_back(num);
        return;
    }

    while (true) {
        curr = tree1[curr].sufflink;
        curr_len = tree1[curr].len;
        if (pos - 1 - curr_len > -1 && s[pos - 1 - curr_len] == s[pos]) {
            tree1[num].sufflink = tree1[curr].nxt[letter];
            tree1[tree1[curr].nxt[letter]].edges.push_back(num);
            break;
        }
    }
}

void init() {
    num = 2, suff = 2;
    tree1[1].len = -1, tree1[1].sufflink = 1;
    tree1[2].len = 0, tree1[2].sufflink = 1;
    tree1[1].edges.push_back(2);
}
ll ans=0;
void dfs(int u){
    for(int x:tree1[u].edges){
        dfs(x);
        tree1[u].cnt+=tree1[x].cnt;
    }   
    MXTO(ans,tree1[u].cnt*tree1[u].len);
}
int32_t main(){
    ios::sync_with_stdio(false),cin.tie(0);
    cin>>s;
    init();
    REP(i,sz(s)){
        add_letter(i);
    }
    dfs(1);
    cout<<ans;
}

• Subtask 1: 8 / 8
• Subtask 2: 15 / 15
• Subtask 3: 24 / 24
• Subtask 4: 26 / 26
• Subtask 5: 27 / 27