제출 #1150630

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1150630		SmuggingSpun	회문 (APIO14_palindrome)	C++20	0 / 100	0 ms	324 KiB

palindrome

#include<bits/stdc++.h>
#define taskname "A"
using namespace std;
typedef long long ll;
template<class T>void maximize(T& a, T b){
	if(a < b){
		a = b;
	}
}
string s;
ll ans = 0;
struct Node{
	int link, len, cnt, child[26];
	Node(){
		memset(this->child, -1, sizeof(this->child));
		this->cnt = 1;
	} 
};
vector<Node>eer(2);
void dfs(int s){
	for(int i = 0; i < 26; i++){
		if(eer[s].child[i] != -1){
			dfs(eer[s].child[i]);
		}
	}
	eer[eer[s].link].cnt += eer[s].cnt;
	maximize(ans, 1LL * eer[s].cnt * eer[s].len);
}
int main(){
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	if(fopen(taskname".inp", "r")){
		freopen(taskname".inp", "r", stdin);
	}
	eer[eer[1].len = eer[0].link = eer[1].link = 0].len = -1;
	cin >> s;
	for(int i = 0, root = 0; i < s.size(); i++){
		s[i] -= 97;
		while(s[i] != s[i - eer[root].len - 1]){
			root = eer[root].link;
		}
		if(eer[root].child[s[i]] == -1){
			int cur = eer[root].child[s[i]] = eer.size();
			eer.emplace_back(Node());
			eer[cur].len = eer[root].len + 2;
			root = eer[root].link;
			while(root != 0 && eer[root].child[s[i]] == -1){
				root = eer[root].link;
			}
			eer[cur].link = (eer[cur].len == 1 || eer[root].child[s[i]] == -1 ? 1 : eer[root].child[s[i]]);
			root = cur;
		}
		else{
			eer[root = eer[root].child[s[i]]].cnt++;
		}
	}
	dfs(0);
	dfs(1);
	cout << ans;
}

컴파일 시 표준 에러 (stderr) 메시지

palindrome.cpp: In function 'int main()':
palindrome.cpp:32:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   32 |                 freopen(taskname".inp", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

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