Submission #1066115

#	Time	Username	Problem	Language	Result	Execution time	Memory
1066115		aufan	Palindromic Partitions (CEOI17_palindromic)	C++17	100 / 100	221 ms	27872 KiB

palindromic

#include <bits/stdc++.h>
#define int long long
#define fi first
#define se second

using namespace std;

const int key = 29;
const int mod = 1e9 + 9;

int32_t main()
{
        ios_base::sync_with_stdio(false);
        cin.tie(NULL);
        
        int t;
        cin >> t;

        while (t --> 0) {
                string s;
                cin >> s;

                int n = (int)s.size();
                vector<int> pr(n + 1);
                for (int i = 0; i < n; i++) {
                        pr[i + 1] = (pr[i] * key + (s[i] - 'a')) % mod;
                }

                vector<int> pw(n + 1);
                pw[0] = 1;
                for (int i = 1; i <= n; i++) pw[i] = (pw[i - 1] * key) % mod;

                auto get = [&](int lf, int rg) {
                        return (pr[rg] - pr[lf - 1] * pw[rg - lf + 1] % mod + mod) % mod;
                };

                int ans = 0;
                for (int i = 1, j = 0; i <= n; i++) {
                        if (get(j + 1, i) == get(n - i + 1, n - j)) {
                                ans += 1;
                                j = i;
                        }
                }

                cout << ans << '\n';
        }
        
        return 0;
}

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