Submission #220975

#	Time	Username	Problem	Language	Result	Execution time	Memory
220975		nafis_shifat	Palindromes (APIO14_palindrome)	C++14	100 / 100	34 ms	36224 KiB

palindrome

#include<bits/stdc++.h>
#define pii pair<int,int>
#define ll long long
using namespace std;
const int mxn=3e5+6;

int tree[mxn][26];
int idx;
int len[mxn];
int link[mxn],t;

char s[mxn];


ll oc[mxn]={};

void init()
{
	len[1]=-1;
    len[2]=0;

    link[1]=link[2]=1;
    idx=t=2;

}
void extend(int p)
{

	while(s[p-len[t]-1]!=s[p])t=link[t];

	int x=link[t];
	int c=s[p]-'a';
    
    while(s[p-len[x]-1]!=s[p])x=link[x];


    if(!tree[t][c])
    {
    	tree[t][c]=++idx;
    	len[idx]=len[t]+2;

    	link[idx]= len[idx]==1 ? 2 : tree[x][c];
    }

    t=tree[t][c];
    oc[t]++;
  
}

 
int main()
{
    init();
	scanf("%s",s+1);



	int n=strlen(s+1);

	for(int i=1;i<=n;i++)extend(i);
	ll res=0;
	for(int i=idx;i>2;i--)
	{
		res=max(res,len[i]*oc[i]);
		oc[link[i]]+=oc[i];
	}
	cout<<res<<endl;

	return 0;
}

Compilation message (stderr)

palindrome.cpp: In function 'int main()':
palindrome.cpp:54:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%s",s+1);
  ~~~~~^~~~~~~~~~

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