Submission #654802

#	Time	Username	Problem	Language	Result	Execution time	Memory
654802		NeroZein	Palindromes (APIO14_palindrome)	C++14	100 / 100	26 ms	35208 KiB

palindrome

#include <bits/stdc++.h>
using namespace std;
const int N = 3e5+10; 
string s;
int num,suff; 
struct node{
    int next[26];
    int len,num,sufflink;
}tree[N]; 

inline void ini(){
    num = suff = 2; 
    tree[1].len = -1;tree[1].sufflink = 1; 
    tree[2].len =  0;tree[2].sufflink = 1; 
}

inline void add(int pos){
    int cur = suff, curlen = 0; 
    int let = s[pos]-'a'; 
    while (true){
        curlen = tree[cur].len;
        if (pos-1-curlen >= 0 && s[pos-1-curlen] == s[pos])
            break; 
        cur = tree[cur].sufflink;
    }
    if (tree[cur].next[let]){
        suff = tree[cur].next[let]; 
        tree[tree[cur].next[let]].num++; 
        return; 
    }
    suff = ++num;
    tree[cur].next[let] = num;
    tree[num].len = tree[cur].len+2; 
    tree[tree[cur].next[let]].num++; 
    if (tree[num].len == 1){
        tree[num].sufflink = 2; 
        return; 
    }
    while(true){
        cur = tree[cur].sufflink;
        curlen = tree[cur].len; 
        if (pos-1-curlen >= 0 && s[pos-1-curlen] == s[pos]){
            tree[num].sufflink = tree[cur].next[let]; 
            break; 
        }
    }
}

int main(){

    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    cin>>s;int n = s.size(); 
    ini(); 
    for(int i=0;i<n;++i)
        add(i); 
    for(int i=n+3;~i;--i)
        tree[tree[i].sufflink].num += tree[i].num;
    long long ans = 0; 
    for(int i=3;i<n+3;i++)
        ans = max(ans, 1LL*tree[i].num*tree[i].len);
    cout<<ans; 
}

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