結果
問題 | No.765 ukuku 2 |
ユーザー |
|
提出日時 | 2022-02-22 19:22:29 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
WA
|
実行時間 | - |
コード長 | 3,600 bytes |
コンパイル時間 | 2,185 ms |
コンパイル使用メモリ | 201,204 KB |
最終ジャッジ日時 | 2025-01-28 01:26:35 |
ジャッジサーバーID (参考情報) |
judge5 / judge5 |
(要ログイン)
ファイルパターン | 結果 |
---|---|
sample | AC * 2 |
other | AC * 40 WA * 8 |
ソースコード
#include <bits/stdc++.h>#define rep(i,n) for(int i = 0; i < (n); i++)using namespace std;typedef long long ll;struct RollingHash {static constexpr int M = 2;static constexpr long long MODS[M] = {999999937, 1000000007};static constexpr long long BASE = 9973;vector<long long> powb[M], hash[M];int n;RollingHash() {}RollingHash(const string& str) { init(str); }void init(const string& str) {n = str.size();for (int k = 0; k < M; k++) {powb[k].resize(n + 1, 1);hash[k].resize(n + 1, 0);for (int i = 0; i < n; i++) {hash[k][i + 1] = (hash[k][i] * BASE + str[i]) % MODS[k];powb[k][i + 1] = powb[k][i] * BASE % MODS[k];}}}// get hash str[l,r)long long get(int l, int r, int k) {long long res = hash[k][r] - hash[k][l] * powb[k][r - l] % MODS[k];if (res < 0) res += MODS[k];return res;}};bool match(RollingHash& rh1, int l1, int r1, RollingHash& rh2, int l2, int r2) {bool res = true;for (int k = 0; k < RollingHash::M; k++) {res &= rh1.get(l1, r1, k) == rh2.get(l2, r2, k);}return res;}int main(){cin.tie(0);ios::sync_with_stdio(0);string S; cin >> S;int N = S.size();string T = S;reverse(T.begin(), T.end());if(S == T) {cout << N - 1 << endl;return 0;}RollingHash HS(S), HT(T);int ans = 0;rep(i,N) {int L = 0, R = min(i, N - (i + 1)) + 1;while(R - L > 1) {int x = (R + L) / 2;(match(HS, i + 1, i + 1 + x, HT, N - i, N - i + x) ? L : R) = x;}if(L == min(i, N - (i + 1))) {ans = max(ans, L + 1 + L);continue;}int SL = L, SR = R;{L = SL, R = SR;int pos = L;R = min(i, N - (i + 2)) + 1;while(R - L > 1) {int x = (R + L) / 2;(match(HS, i + 2 + pos, i + 2 + x, HT, N - i + pos, N - i + x) ? L : R) = x;}ans = max(ans, L + 1 + L);}{L = SL, R = SR;int pos = L;R = min(i - 1, N - (i + 1)) + 1;while(R - L > 1) {int x = (R + L) / 2;(match(HS, i + pos, i + 1 + x, HT, N - i + pos + 1, N - i + x + 1) ? L : R) = x;}ans = max(ans, L + 1 + L);}}rep(i,N-1) if(S[i] == S[i + 1]) {int L = 0, R = min(i, N - (i + 2)) + 1;while(R - L > 1) {int x = (R + L) / 2;(match(HS, i + 2, i + 2 + x, HT, N - i, N - i + x) ? L : R) = x;}if(L == min(i, N - (i + 2))) {ans = max(ans, L + 2 + L);continue;}int SL = L, SR = R;{L = SL, R = SR;int pos = L;R = min(i, N - (i + 3)) + 1;while(R - L > 1) {int x = (R + L) / 2;(match(HS, i + 3 + pos, i + 3 + x, HT, N - i + pos, N - i + x) ? L : R) = x;}ans = max(ans, L + 2 + L);}{L = SL, R = SR;int pos = L;R = min(i - 1, N - (i + 2)) + 1;while(R - L > 1) {int x = (R + L) / 2;(match(HS, i + 2 + pos, i + 2 + x, HT, N - i + pos + 1, N - i + x + 1) ? L : R) = x;}ans = max(ans, L + 2 + L);}}cout << ans << endl;}