Submission #885038

#	Time	Username	Problem	Language	Result	Execution time	Memory
885038		patrikpavic2	Palindromes (APIO14_palindrome)	C++17	0 / 100	5 ms	1272 KiB

palindrome

#include <algorithm>
#include <vector>
#include <cstdio>
#include <cstring>
#include <iostream>
 
#define PB push_back
 
using namespace std;
 
typedef long long ll;
 
const int N = 3e5 + 500;
const int INF = 0x3f3f3f3f;
 
struct node{
    node *ch[30], *bk;
    int len, cnt;
    node() {}
    node(int _len) { len = _len; }
};
 
bool cmp(node* X, node* Y){
    return X->len > Y->len;
}
 
string s;
int n;
ll mx;
vector < node* > v;
 
void precompute(){
    node *n1 = new node(); 
    node *n0 = new node();
    n1->len = -1, n0->len = 0;
    n0->bk = n1; n1->bk = n1;
    node* cur = n0;
    for(int i = 0;i < n;i++){
        for(; cur->len + 1 > i || s[i - cur->len - 1] != s[i]; cur = cur->bk);
        node *rmb = cur->bk;
        if(cur->ch[s[i] - 'a'] == NULL)
            cur->ch[s[i] - 'a'] = new node(), v.PB(cur->ch[s[i] - 'a']);
        cur->ch[s[i] - 'a']->len = cur->len + 2;
        cur = cur->ch[s[i] - 'a'];
        cur->cnt++;
        for(; rmb->len + 1 > i || s[i - rmb->len - 1] != s[i]; rmb = rmb->bk);
        if(cur->len == 1)
            cur->bk = n0;
        else{
            if(rmb->ch[s[i] - 'a'] == NULL)
                rmb->ch[s[i] - 'a'] = new node(), v.PB(rmb->ch[s[i] - 'a']);
            cur->bk = rmb->ch[s[i] - 'a'];
        }
    }
}
 
 
 
int main(){
	cin >> s;
	n = (int)s.size();
    precompute();
    sort(v.begin(), v.end(), cmp);
    for(int i = 0;i < v.size();i++){
        mx = max(mx, (ll)v[i]->len * v[i]->cnt);
        v[i]->bk->cnt += v[i]->cnt;
    }
    cout << mx << endl;
}

Compilation message (stderr)

palindrome.cpp: In function 'int main()':
palindrome.cpp:64:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<node*>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   64 |     for(int i = 0;i < v.size();i++){
      |                   ~~^~~~~~~~~~

• Subtask 1: 0 / 8
• Subtask 2: 0 / 15
• Subtask 3: 0 / 24
• Subtask 4: 0 / 26
• Subtask 5: 0 / 27