Submission #99173

#	Time	Username	Problem	Language	Result	Execution time	Memory
99173		mirbek01	Palindromes (APIO14_palindrome)	C++11	47 / 100	1066 ms	2752 KiB

palindrome

# include <bits/stdc++.h>

using namespace std;

const int N = 1e4 + 2;

int n, bor[26][N], cnt[N * 27], cn = 1;
long long ans;
string s;

void add(int id, int c){
      int v = 1;
      for(int len = 0; len < min(n - id + 1, id); len ++){
            if(id - len <= 0 || id + len + c > n || s[id - len] != s[id + len + c]){
                  break;
            }
            int now = s[id - len] - 'a';
            if(!bor[now][v]){
                  bor[now][v] = ++ cn;
            }
            v = bor[now][v];
            cnt[v] ++;
      }
}

void f(int v, int len, int c){
      for(int i = 0; i < 26; i ++){
            if(bor[i][v]){
                  ans = max(ans, (len * 2 - c) *1ll* cnt[bor[i][v]]);
                  f(bor[i][v], len + 1, c);
            }
      }
}

int main(){
      cin >> s;
      n = s.size();
      s = ' ' + s;

      for(int i = 1; i <= n; i ++){
            add(i, 0);
      }

      f(1, 1, 1);
      cn = 1;
      memset(bor, 0, sizeof(bor));
      memset(cnt, 0, sizeof(cnt));

      for(int i = 1; i < n; i ++){
            if(s[i] == s[i + 1])
                  add(i, 1);
      }

      f(1, 1, 0);

      cout << ans << endl;
}

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