제출 #582959

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
582959		600Mihnea	Palindromic Partitions (CEOI17_palindromic)	C++17	60 / 100	10017 ms	12192 KiB

palindromic

#include <bits/stdc++.h>

using namespace std;

typedef long double ld;
typedef long long ll;

const int N = (int) 1e6 + 7;
const int INF = (int) 1e9 + 7;
int n;
int a[N];
int dp[N];
int big[N];

bool is_palind(int l, int r) {
  if (l > r) {
    return 1;
  }
  return a[l] == a[r] && is_palind(l + 1, r - 1);
}

signed main() {
  ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

 /// freopen ("input.txt", "r", stdin);

  int Tests;
  cin >> Tests;
  for (int tc = 1; tc <= Tests; tc++) {
    {
      string str;
      cin >> str;
      n = (int) str.size();
      int Low = 0, High = n - 1;
      for (int Step = 1; Step <= n; Step++) {
        if (Step % 2 == 0) {
          a[Step] = str[Low++] - 'a';
        } else {
          a[Step] = str[High--] - 'a';
        }
      }
    }

    for (int i = 0; i <= n + 1; i++) {
      dp[i] = -INF;
      big[i] = 0;
    }
    dp[0] = 0;
    for (int i = n - 1; i >= 1; i--) {
      int l = i, r = i + 1;
      while (1 <= l && r <= n && a[l] == a[r]) {
        if (big[r] == 0) {
          big[r] = i;
        }
        l--;
        r++;
      }
    }
    for (int r = 1; r <= n; r++) {
      if (int i = big[r]) {
        int l = 2 * i + 1 - r;
        dp[r] = max(dp[r], dp[l - 1] + 1);
      }
    }
    int sol = 2 * dp[n];
    for (int i = 0; i < n; i++) {
      sol = max(sol, 2 * dp[i] + 1);
    }
    cout << sol << "\n";
  }
}

• Subtask 1: 15 / 15
• Subtask 2: 20 / 20
• Subtask 3: 25 / 25
• Subtask 4: 0 / 40