#include <bits/stdc++.h>
using namespace std;
class HashString {
public:
const int KEY = 37;
const int MOD = 1e9 + 9;
int N;
string S;
vector<int> H;
vector<int> power;
vector<int> inv_power;
HashString(string S) : S(S) {
N = S.size();
H.resize(N);
power.resize(N);
inv_power.resize(N);
const auto Power = [&](int a, int x) {
int z = 1;
while (x) {
if (x & 1) z = 1ll * z * a % MOD;
x /= 2;
a = 1ll * a * a % MOD;
}
return z;
};
power[0] = inv_power[0] = 1;
power[1] = KEY;
inv_power[1] = Power(KEY, MOD - 2);
for (int i = 2; i < N; i++) {
power[i] = 1ll * KEY * power[i - 1] % MOD;
inv_power[i] = 1ll * inv_power[i - 1] * inv_power[1] % MOD;
}
for (int i = 0; i < N; i++) {
assert(1ll * power[i] * inv_power[i] % MOD == 1);
}
for (int i = 0; i < N; i++) {
H[i] = ((i > 0 ? H[i - 1] : 0) + 1ll * (S[i] - 'a' + 1) * power[i]) % MOD;
}
}
int GetHash(int L, int R) {
int res = (H[R] + MOD - (L > 0 ? H[L - 1] : 0)) % MOD;
return 1ll * res * inv_power[L] % MOD;
}
};
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
string S, T;
cin >> S >> T;
const auto Solve = [&]() -> array<int, 3> {
int N = S.size();
int M = T.size();
array<int, 3> ans = {0, 0, 0};
HashString HS = HashString(S);
HashString HT = HashString(T);
// cout << HS.GetHash(2, 3) << ' ' << HT.GetHash(1, 2) << " hm\n";
for (int t = 0; t < M; t++) {
vector<int> dp(N);
// dp[s] = longest suffix of T[0...t-1] which is a prefix of S[s...N]
for (int s = 0; s < N; s++) {
int lo = 0, hi = max(N, M);
while (lo < hi) {
int md = (lo + hi + 1) / 2;
if (0 <= s - md && 0 <= t - md &&
HS.GetHash(s - md + 1, s) == HT.GetHash(t - md, t - 1)) {
lo = md;
} else {
hi = md - 1;
}
}
// cout << s << ' ' << t << ' ' << lo << " getdp\n";
dp[s - lo + 1] = max(dp[s - lo + 1], lo);
}
for (int s = 1; s < N; s++) {
dp[s] = max(dp[s], dp[s - 1] - 1);
}
// cout << "DP: ";
// for (int s = 0; s < N; s++) {
// cout << dp[s] << ' ';
// }
// cout << '\n';
for (int s = 0; s < N; s++) {
// Get longest common prefix starting with S[s...N], T[t...M]
int lo = 0, hi = max(N, M);
while (lo < hi) {
int md = (lo + hi + 1) / 2;
if (s + md <= N && t + md <= M &&
HS.GetHash(s, s + md - 1) == HT.GetHash(t, t + md - 1)) {
lo = md;
} else {
hi = md - 1;
}
}
// S[s...s + lo - 1] == T[t...t + lo - 1]
// Then, answer is lo + dp[s + lo]
int len = lo + dp[s + lo];
ans = max(ans, {len, s, t - dp[s + lo]});
// cout << s << ' ' << t << ' ' << lo << ' ' << dp[s + lo] << " ha\n";
}
}
return ans;
};
auto ans1 = Solve();
reverse(begin(T), end(T));
auto ans2 = Solve();
ans2[2] = int(T.size()) - ans2[2] - ans2[0];
auto ans = max(ans1, ans2);
// auto ans = Solve();
cout << ans[0] << '\n' << ans[1] << ' ' << ans[2] << '\n';
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
7 ms |
204 KB |
Output is correct |
| 2 |
Correct |
7 ms |
204 KB |
Output is correct |
| 3 |
Correct |
6 ms |
204 KB |
Output is correct |
| 4 |
Correct |
6 ms |
272 KB |
Output is correct |
| 5 |
Incorrect |
6 ms |
204 KB |
Output isn't correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
7 ms |
204 KB |
Output is correct |
| 2 |
Correct |
7 ms |
204 KB |
Output is correct |
| 3 |
Correct |
6 ms |
204 KB |
Output is correct |
| 4 |
Correct |
6 ms |
272 KB |
Output is correct |
| 5 |
Incorrect |
6 ms |
204 KB |
Output isn't correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
7 ms |
204 KB |
Output is correct |
| 2 |
Correct |
7 ms |
204 KB |
Output is correct |
| 3 |
Correct |
6 ms |
204 KB |
Output is correct |
| 4 |
Correct |
6 ms |
272 KB |
Output is correct |
| 5 |
Incorrect |
6 ms |
204 KB |
Output isn't correct |
