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답안 #551945

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
551945 2022-04-21T23:27:05 Z Bungmint Palinilap (COI16_palinilap) C++17
100 / 100
 113 ms 66500 KB 
//Copyright © 2022 Youngmin Park. All rights reserved.
//#pragma GCC optimize("O3")
//#pragma GCC target("avx2")
#include <bits/stdc++.h>
using namespace std;

#define int long long
using ll = long long;
using vi = vector<int>;
using pii = pair<int, int>;
using vpi = vector<pii>;
using pll = pair<ll, ll>;
using vl = vector<ll>;
using vpl = vector<pll>;
using ld = long double;
template <typename T, size_t SZ>
using ar = array<T, SZ>;

#define all(v) (v).begin(), (v).end()
#define pb push_back
#define sz(x) (int)(x).size()
#define fi first
#define se second
#define lb lower_bound
#define ub upper_bound
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define F0R(i, a) FOR(i, 0, a)
#define ROF(i, a, b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i, a) ROF(i, 0, a)
#define REP(a) F0R(_, a)

const int INF = 1e9;
const ll LINF = 1e18;
const int MOD = 1e9 + 7; //998244353;
const ld PI = acos((ld)-1.0);
const int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
template <typename T>
using pqg = priority_queue<T, vector<T>, greater<T>>;
template <typename T>
bool ckmin(T &a, const T &b) { return b < a ? a = b, 1 : 0; }
template <typename T>
bool ckmax(T &a, const T &b) { return b > a ? a = b, 1 : 0; }

template <typename A, typename B>
ostream &operator<<(ostream &os, const pair<A, B> &p)
{
    return os << '(' << p.first << ", " << p.second << ')';
}
template <typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type>
ostream &operator<<(ostream &os, const T_container &v)
{
    os << '{';
    string sep;
    for (const T &x : v)
        os << sep << x, sep = ", ";
    return os << '}';
}
void dbg_out()
{
    cerr << endl;
}
template <typename Head, typename... Tail>
void dbg_out(Head H, Tail... T)
{
    cerr << ' ' << H;
    dbg_out(T...);
}
#ifdef LOCAL
#define dbg(...) cerr << "(" << #__VA_ARGS__ << "):", dbg_out(__VA_ARGS__)
#else
#define dbg(...) 42
#endif

inline namespace RecursiveLambda{
	template <typename Fun>
	struct y_combinator_result{
		Fun fun_;
		template <typename T> 
		explicit y_combinator_result(T &&fun): fun_(forward<T>(fun)){}
		template <typename...Args>
		decltype(auto) operator()(Args &&...args){
			return fun_(ref(*this), forward<Args>(args)...);
		}
	};
	template <typename Fun>
	decltype(auto) y_combinator(Fun &&fun){
		return y_combinator_result<decay_t<Fun>>(forward<Fun>(fun));
	}
};

void setIO(string s) // USACO
{
	#ifndef LOCAL
	    freopen((s + ".in").c_str(), "r", stdin);
	    freopen((s + ".out").c_str(), "w", stdout);
	#endif
}

constexpr int B = 9973;

int add(int a, int b) {
	a += b;
	if (a >= MOD) a -= MOD;
	return a;
}
int mul(int a, int b) {
	return 1LL * a * b % MOD;
}
int sub(int a, int b) {
	a -= b;
	if (a < 0) a += MOD;
	return a;
}
int binPow(int a, int b) {
	ll res = 1;
	while (b) {
		if (b & 1) res = (res * a) % MOD;
		a = (1LL * a * a) % MOD;
		b >>= 1LL;
	}
	return res;
}


struct HashRange {
	vi t, power, inv;
	HashRange(string &s) {
		int n = sz(s);
		t.resize(n + 1);
		power.resize(n + 1);
		inv.resize(n + 1);
		power[0] = inv[0] = 1;
		inv[1] = binPow(B, MOD - 2);
		FOR(i, 1, n + 1) inv[i] = mul(inv[i - 1], inv[1]);
		FOR(i, 1, n + 1) power[i] = mul(power[i - 1], B);
		F0R(i, n) {
			t[i + 1] = add(t[i], mul(power[i], s[i]));
		}
	}
	int calcHash(int l, int r) { // 0 - indexed
		return mul(sub(t[r + 1], t[l]), inv[l]);
	}
};

void solve()
{
	string s, t;
	cin >> s;
	int n = sz(s);
	F0R(i, n) {
		t += '#';
		t += s[i];
	}
	t += '#';
	HashRange hshF(t);
	reverse(all(t));
	HashRange hshB(t);
	int nn = sz(t);
	vi rd(nn);
	vector<vi> a(nn, vi(26));
	ll tot{}, ans{0};
	reverse(all(t));
	F0R(i, nn) {
		int l = 0, r = min(i, nn - 1 - i), ret = 0;
		while (l <= r) {
			int mid = (l + r) >> 1;
			if (hshF.calcHash(i, i + mid) == hshB.calcHash(nn - 1 - i, nn - 1 - i + mid)) {
				ret = mid; l = mid + 1;
			}else r = mid - 1;
		}
		rd[i] = ret;
		if (i & 1) {
			tot += (ret + 1) / 2;
		}else tot += ret / 2;
		
		if (i - ret > 0 && i + ret + 1 < nn) {
			char c = t[i + ret + 1];
			char d = t[i - ret - 1];
			dbg(i, c, d);
			l = 1, r = min(i - ret - 1, nn - 1 - i - ret - 1);
			int z = 0;
			while (l <= r) {
				int mid = (l + r) >> 1;
				if (hshF.calcHash(i + ret + 2, i + ret + 1 + mid) == hshB.calcHash(nn - 1 - (i - ret - 2), nn - 1 - (i - ret - 1) + mid)) {
					z = mid, l = mid + 1;
				}else r = mid - 1;
			}
			a[i - ret - 1][c - 'a'] += z / 2 + 1;
			a[i + ret + 1][d - 'a'] += z / 2 + 1;
			dbg(z);
		}
	}
	int sum{}, cnt{};
	vpi fr(nn);
	vpi bk(nn);
	F0R(i, nn) {
		char c = t[i];
		if (c != '#') {
			int z = (sum - (i + 1) * cnt) / 2 + cnt;
			F0R(j, 26) {
				if (j == c - 'a') continue;
				a[i][j] -= z;
			}
		}
		sum += i + rd[i];
		cnt++;
		fr[i + rd[i]].fi += i + rd[i];
		fr[i + rd[i]].se++;
		sum -= fr[i].fi;
		cnt -= fr[i].se;
	}
	cnt = sum = 0;
	R0F(i, nn) {
		char c = t[i];
		if (c != '#') {
			int z = ((i - 1) * cnt - sum) / 2 + cnt;
			dbg(z);
			F0R(j, 26) {
				if (j == c - 'a') continue;
				a[i][j] -= z;
			}
		}
		sum += i - rd[i];
		cnt++;
		bk[i - rd[i]].fi += i - rd[i];
		bk[i - rd[i]].se++;
		sum -= bk[i].fi;
		cnt -= bk[i].se;
	}
	F0R(i, nn) {
		if (i & 1) {
			F0R(j, 26) {
				ckmax(ans, tot + a[i][j]);
			}
		}
	}
	cout << ans << '\n';
	
}

int32_t main()
{
    cin.tie(0)->sync_with_stdio(0);
    cin.exceptions(cin.failbit);
    int testcase=1;
    // cin >> testcase;
    while (testcase--)
    {
        solve();
    }
}

Compilation message

palinilap.cpp: In function 'void solve()':
palinilap.cpp:72:18: warning: statement has no effect [-Wunused-value]
   72 | #define dbg(...) 42
      |                  ^~
palinilap.cpp:180:4: note: in expansion of macro 'dbg'
  180 |    dbg(i, c, d);
      |    ^~~
palinilap.cpp:72:18: warning: statement has no effect [-Wunused-value]
   72 | #define dbg(...) 42
      |                  ^~
palinilap.cpp:191:4: note: in expansion of macro 'dbg'
  191 |    dbg(z);
      |    ^~~
palinilap.cpp:72:18: warning: statement has no effect [-Wunused-value]
   72 | #define dbg(...) 42
      |                  ^~
palinilap.cpp:218:4: note: in expansion of macro 'dbg'
  218 |    dbg(z);
      |    ^~~
palinilap.cpp: In function 'void setIO(std::string)':
palinilap.cpp:95:13: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   95 |      freopen((s + ".in").c_str(), "r", stdin);
      |      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
palinilap.cpp:96:13: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   96 |      freopen((s + ".out").c_str(), "w", stdout);
      |      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
17.0 / 17.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 324 KB Output is correct
4 Correct 1 ms 328 KB Output is correct
5 Correct 1 ms 340 KB Output is correct

Subtask #2
37.0 / 37.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 3540 KB Output is correct
2 Correct 4 ms 3536 KB Output is correct
3 Correct 5 ms 3540 KB Output is correct
4 Correct 3 ms 2244 KB Output is correct
5 Correct 4 ms 3112 KB Output is correct
6 Correct 5 ms 3540 KB Output is correct
7 Correct 5 ms 3540 KB Output is correct

Subtask #3
46.0 / 46.0

# 결과 실행 시간 메모리 Grader output
1 Correct 111 ms 66472 KB Output is correct
2 Correct 94 ms 66368 KB Output is correct
3 Correct 84 ms 66488 KB Output is correct
4 Correct 103 ms 66372 KB Output is correct
5 Correct 101 ms 66364 KB Output is correct
6 Correct 104 ms 66368 KB Output is correct
7 Correct 107 ms 66372 KB Output is correct
8 Correct 82 ms 66456 KB Output is correct
9 Correct 104 ms 66364 KB Output is correct
10 Correct 107 ms 66388 KB Output is correct
11 Correct 94 ms 66500 KB Output is correct
12 Correct 107 ms 66452 KB Output is correct
13 Correct 112 ms 66484 KB Output is correct
14 Correct 104 ms 66472 KB Output is correct
15 Correct 113 ms 66456 KB Output is correct
16 Correct 100 ms 66416 KB Output is correct
17 Correct 99 ms 66368 KB Output is correct
18 Correct 108 ms 66364 KB Output is correct
19 Correct 100 ms 66476 KB Output is correct