Submission #965542

#	Time	Username	Problem	Language	Result	Execution time	Memory
965542		Alkaser_ID	Copy and Paste 3 (JOI22_copypaste3)	C++17	20 / 100	3084 ms	1524 KiB

copypaste3

#include <iostream>
#include <algorithm>
#include <vector>
#include <map>
#include <set>
using namespace std;
typedef long long ll;
const ll mod = 1e9 + 7;
#define ml(x,y) ((x*y)%mod)
ll b1 = 53, p1[3003];
ll inv[3003];

ll a, b, c;
ll hsh[3003];
map<ll, ll> dp;
inline ll fsp(ll x, ll b) {
	if (b == 0) return 1;
	if (b == 1) return x;
	ll g = ml(x, x);
	g = fsp(g, b / 2);
	if (b % 2 == 0) return g;
	return (g * x) % mod;
}
inline ll small(ll l,ll r) {
	ll sz = r - l + 1;
	if (sz == 1) return a;
	if (sz == 2) {
		ll fr = (hsh[l] - (l == 0 ? 0 : hsh[l - 1])) % mod; 
		ll sc = (hsh[l + 1] - hsh[l] + mod) % mod;
		sc = (sc * inv[1]) % mod;
		if (fr == sc) return min(2 * a, a + b + 2 * c);
		return 2 * a;
	}
	ll fr = (hsh[l] - (l == 0 ? 0 : hsh[l - 1])) % mod;
	ll sc = (hsh[l + 1] - hsh[l] + mod) % mod;
	ll th = (hsh[l + 2] - hsh[l + 1] + mod) % mod;
	sc = (sc * inv[1]) % mod;
	th = (th * inv[2]) % mod;
	if (sc != fr && fr != th && sc != th) return 3 * a;
	if (sc == fr && fr == th) return min(3 * a, a + b + 3 * c);
	return min(3 * a, 2 * a + b + 2 * c);
}
inline ll getmin(ll l, ll r) {
	ll th = hsh[r] - (l == 0 ? 0 : hsh[l - 1]);
	th = (th * inv[l]) % mod;
	if (dp.find(th) != dp.end()) return dp[th];
	if (r - l + 1 <= 3) return small(l, r);
	ll dc = 0, tot = (r - l + 1) * a;
	for (ll ln = 1; ln <= (r - l + 1) / 2; ++ln) {
		if (a * ln <= c) continue;
		map<ll, ll> m, d; map<ll, pair<ll, ll>> st;
		for (ll i = l; i + ln <= r + 1; ++i) {
			ll j = i + ln - 1;
			ll hs = (hsh[j] - (i > 0 ? hsh[i - 1] : 0) + mod) % mod;
			hs = (hs * inv[i]) % mod;
			if (m.find(hs) != m.end()) {
				if (i < d[hs]) continue;
			}
			else st[hs] = { i,j };
			d[hs] = i + ln;
			++m[hs];
		}
		for (map<ll, ll>::iterator it = m.begin(); it != m.end(); ++it) {
			pair<ll, ll> se = st[it->first];
			ll prp = getmin(se.first, se.second);
			ll tcost = it->second * ln * a - prp - it->second * c - b;
			if (tcost <= 0) continue;
			dc = max(dc, tcost);
		}
	}
	dp[th] = tot - dc;
	return tot - dc;
}
int main()
{
	ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	ll n; cin >> n;
	string s; cin >> s;
	cin >> a >> b >> c;
	p1[0] = 1;
	p1[1] = b1; 
	for (ll i = 2; i <= s.size() + 3; ++i) {
		p1[i] = (p1[i - 1] * b1) % mod;
	}
	inv[0] = 1;
	for (ll i = 1; i <= s.size(); ++i) {
		inv[i] = fsp(p1[i], mod - 2);
	}
	ll lst = 0;
	for (ll i = 0; i < s.size(); ++i) {
		hsh[i] = ((s[i] - 95) * p1[i]) % mod;
		hsh[i] = (hsh[i] + lst) % mod;
		lst = hsh[i];
	}
	cout << getmin(0, n - 1);
}

Compilation message (stderr)

copypaste3.cpp: In function 'int main()':
copypaste3.cpp:82:19: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   82 |  for (ll i = 2; i <= s.size() + 3; ++i) {
      |                 ~~^~~~~~~~~~~~~~~
copypaste3.cpp:86:19: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   86 |  for (ll i = 1; i <= s.size(); ++i) {
      |                 ~~^~~~~~~~~~~
copypaste3.cpp:90:19: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   90 |  for (ll i = 0; i < s.size(); ++i) {
      |                 ~~^~~~~~~~~~

• Subtask 1: 1 / 1
• Subtask 2: 5 / 5
• Subtask 3: 14 / 14
• Subtask 4: 0 / 10
• Subtask 5: 0 / 32
• Subtask 6: 0 / 38