結果
| 問題 |
No.3119 A Little Cheat
|
| コンテスト | |
| ユーザー |
 PNJ
|
| 提出日時 | 2025-04-18 23:58:41 |
| 言語 | C++23 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
AC
|
| 実行時間 | 130 ms / 2,000 ms |
| コード長 | 11,496 bytes |
| コンパイル時間 | 3,404 ms |
| コンパイル使用メモリ | 295,512 KB |
| 実行使用メモリ | 14,932 KB |
| 最終ジャッジ日時 | 2025-04-18 23:58:52 |
| 合計ジャッジ時間 | 9,578 ms |
|
ジャッジサーバーID （参考情報） |
judge5 / judge4 |
（要ログイン）
| ファイルパターン | 結果 |
|---|---|
| sample | AC * 3 |
| other | AC * 49 |
ソースコード
#include <bits/stdc++.h>
#include <bit>
using namespace std;
template <class T>
using vc = vector<T>;
template <class T>
using vvc = vector<vc<T>>;
template <class T>
using vvvc = vector<vvc<T>>;
template <class T>
using vvvvc = vector<vvvc<T>>;
template <class T>
using vvvvvc = vector<vvvvc<T>>;
#define vv(type, name, h, w) vector<vector<type>> name(h, vector<type>(w))
#define vvv(type, name, h, w, l) vector<vector<vector<type>>> name(h, vector<vector<type>>(w, vector<type>(l)))
#define vvvv(type, name, a, b, c, d) vector<vector<vector<vector<type>>>> name(a, vector<vector<vector<type>>>(b, vector<vector<type>>(c, vector<type>(d))))
#define vvvvv(type, name, a, b, c, d, e) vector<vector<vector<vector<vector<type>>>>> name(a, vector<vector<vector<vector<type>>>>(b, vector<vector<vector<type>>>(c, vector<vector<type>>(d, vector<type>(e)))))
#define elif else if
#define FOR1(a) for (long long _ = 0; _ < (long long)(a); _++)
#define FOR2(i, n) for (long long i = 0; i < (long long)(n); i++)
#define FOR3(i, l, r) for (long long i = l; i < (long long)(r); i++)
#define FOR4(i, l, r, c) for (long long i = l; i < (long long)(r); i += c)
#define FOR1_R(a) for (long long _ = (long long)(a) - 1; _ >= 0; _--)
#define FOR2_R(i, n) for (long long i = (long long)(n) - 1; i >= (long long)(0); i--)
#define FOR3_R(i, l, r) for (long long i = (long long)(r) - 1; i >= (long long)(l); i--)
#define FOR4_R(i, l, r, c) for (long long i = (long long)(r) - 1; i >= (long long)(l); i -= (c))
#define overload4(a, b, c, d, e, ...) e
#define FOR(...) overload4(__VA_ARGS__, FOR4, FOR3, FOR2, FOR1)(__VA_ARGS__)
#define FOR_R(...) overload4(__VA_ARGS__, FOR4_R, FOR3_R, FOR2_R, FOR1_R)(__VA_ARGS__)
#define FOR_in(a, A) for (auto a: A)
#define FOR_each(a, A) for (auto &&a: A)
#define FOR_subset(t, s) for(long long t = (s); t >= 0; t = (t == 0 ? -1 : (t - 1) & (s)))
#define all(x) x.begin(), x.end()
#define len(x) int(x.size())
int popcount(int x) { return __builtin_popcount(x); }
int popcount(uint32_t x) { return __builtin_popcount(x); }
int popcount(long long x) { return __builtin_popcountll(x); }
int popcount(uint64_t x) { return __builtin_popcountll(x); }
// __builtin_clz(x)は最上位bitからいくつ0があるか.
int topbit(int x) { return (x == 0 ? -1 : 31 - __builtin_clz(x)); }
int topbit(uint32_t x) { return (x == 0 ? -1 : 31 - __builtin_clz(x)); }
int topbit(long long x) { return (x == 0 ? -1 : 63 - __builtin_clzll(x)); }
int topbit(uint64_t x) { return (x == 0 ? -1 : 63 - __builtin_clzll(x)); }
// 入力
void rd() {}
void rd(char &c) { cin >> c; }
void rd(string &s) { cin >> s; }
void rd(int &x) { cin >> x; }
void rd(uint32_t &x) { cin >> x; }
void rd(long long &x) { cin >> x; }
void rd(uint64_t &x) { cin >> x; }
template<class T>
void rd(vector<T> &v) {
for (auto& x:v) rd(x);
}
void read() {}
template <class H, class... T>
void read(H &h, T &... t) {
rd(h), read(t...);
}
#define CHAR(...) \
char __VA_ARGS__; \
read(__VA_ARGS__)
#define STRING(...) \
string __VA_ARGS__; \
read(__VA_ARGS__)
#define INT(...) \
int __VA_ARGS__; \
read(__VA_ARGS__)
#define U32(...) \
uint32_t __VA_ARGS__; \
read(__VA_ARGS__)
#define LL(...) \
long long __VA_ARGS__; \
read(__VA_ARGS__)
#define U64(...) \
uint64_t __VA_ARGS__; \
read(__VA_ARGS__)
#define VC(t, a, n) \
vector<t> a(n); \
read(a)
#define VVC(t, a, h, w) \
vector<vector<t>> a(h, vector<t>(w)); \
read(a)
//出力
void wt() {}
void wt(const char c) { cout << c; }
void wt(const string s) { cout << s; }
void wt(int x) { cout << x; }
void wt(uint32_t x) { cout << x; }
void wt(long long x) { cout << x; }
void wt(uint64_t x) { cout << x; }
void wt(double x) { cout << fixed << setprecision(16) << x; }
void wt(long double x) { cout << fixed << setprecision(16) << x; }
template<class T>
void wt(const vector<T> v) {
int n = v.size();
for (int i = 0; i < n; i++) {
if (i) wt(' ');
wt(v[i]);
}
}
void print() { wt('\n'); }
template <class Head, class... Tail>
void print(Head &&head, Tail &&... tail) {
wt(head);
if (sizeof...(Tail)) wt(' ');
print(forward<Tail>(tail)...);
}
/////////////////////////////////////////////////////////////////////////////////////////
uint64_t random_u64(uint64_t l, uint64_t r) {
static std::random_device rd;
static std::mt19937_64 gen(rd());
std::uniform_int_distribution<uint64_t> dist(l, r);
return dist(gen);
}
long long gcd(long long a, long long b) {
while (a) {
b %= a;
if (b == 0) return a;
a %= b;
}
return b;
}
long long lcm(long long a, long long b) {
if (a * b == 0) return 0;
return a * b / gcd(a, b);
}
long long pow_mod(long long a, long long r, long long mod) {
long long res = 1, p = a % mod;
while (r) {
if ((r % 2) == 1) res = res * p % mod;
p = p * p % mod, r >>= 1;
}
return res;
}
long long mod_inv(long long a, long long mod) {
if (mod == 1) return 0;
a %= mod;
long long b = mod, s = 1, t = 0;
while (1) {
if (a == 1) return s;
t -= (b / a) * s;
b %= a;
if (b == 1) return t + mod;
s -= (a / b) * t;
a %= b;
}
}
long long Garner(vector<long long> Rem, vector<long long> Mod, int MOD) {
assert (Rem.size() == Mod.size());
long long mod = MOD;
Rem.push_back(0);
Mod.push_back(mod);
long long n = Mod.size();
vector<long long> coffs(n, 1);
vector<long long> constants(n, 0);
for (int i = 0; i < n - 1; i++) {
long long v = (Mod[i] + Rem[i] - constants[i]) % Mod[i];
v *= mod_inv(coffs[i], Mod[i]);
v %= Mod[i];
for (int j = i + 1; j < n; j++) {
constants[j] = (constants[j] + coffs[j] * v) % Mod[j];
coffs[j] = (coffs[j] * Mod[i]) % Mod[j];
}
}
return constants[n - 1];
}
long long Tonelli_Shanks(long long a, long long mod) {
a %= mod;
if (a < 2) return a;
if (pow_mod(a, (mod - 1) / 2, mod) != 1) return -1;
if (mod % 4 == 3) return pow_mod(a, (mod + 1) / 4, mod);
long long b = 3;
if (mod != 998244353) {
while (pow_mod(b, (mod - 1) / 2, mod) == 1) {
b = random_u64(2, mod - 1);
}
}
long long q = mod - 1;
long long Q = 0;
while (q % 2 == 0) {
Q++, q /= 2;
}
long long x = pow_mod(a, (q + 1) / 2, mod);
b = pow_mod(b, q, mod);
long long shift = 2;
while ((x * x) % mod != a) {
long long error = (((pow_mod(a, mod - 2, mod) * x) % mod) * x) % mod;
if (pow_mod(error, 1 << (Q - shift), mod) != 1) {
x = (x * b) % mod;
}
b = (b * b) % mod;
shift++;
}
return x;
}
/////////////////////////////////////////////////////////////////////////////////////////
template <int mod>
struct modint {
static constexpr uint32_t umod = uint32_t(mod);
static_assert(umod < (uint32_t(1) << 31));
uint32_t val;
static modint raw(uint32_t v) {
modint x;
x.val = v % umod;
return x;
}
constexpr modint() : val(0) {}
constexpr modint(uint32_t x) : val(x % umod) {}
constexpr modint(uint64_t x) : val(x % umod) {}
constexpr modint(__uint128_t x) : val(x % umod) {}
constexpr modint(int x) : val((x %= int(umod)) < 0 ? x + umod : x) {};
constexpr modint(long long x) : val((x %= int(umod)) < 0 ? x + umod : x) {};
constexpr modint(__int128_t x) : val((x %= int(umod)) < 0 ? x + umod : x) {};
bool operator<(const modint &other) const { return val < other.val; }
modint &operator+=(const modint &p) {
if ((val += p.val) >= umod) val -= umod;
return *this;
}
modint &operator-=(const modint &p) {
if ((val += umod - p.val) >= umod) val -= umod;
return *this;
}
modint &operator*=(const modint &p) {
val = uint64_t(val) * p.val % umod;
return *this;
}
modint &operator/=(const modint &p) {
val = uint64_t(val) * p.inverse().val % umod;
return *this;
}
modint operator-() const { return modint::raw(val ? umod - val : uint32_t(0)); }
modint operator+(const modint &p) const { return modint(*this) += p; }
modint operator-(const modint &p) const { return modint(*this) -= p; }
modint operator*(const modint &p) const { return modint(*this) *= p; }
modint operator/(const modint &p) const { return modint(*this) /= p; }
bool operator==(const modint &p) const { return val == p.val; }
bool operator!=(const modint &p) const { return val != p.val; }
modint inverse() const {
int a = val, b = umod, s = 1, t = 0;
while (1) {
if (a == 1) return modint(s);
t -= (b / a) * s;
b %= a;
if (b == 1) return modint(t + umod);
s -= (a / b) * t;
a %= b;
}
}
modint pow(long long n) const {
n %= (long long)(umod);
if (n < 0) n += umod - 1;
modint res(1), a(val);
while (n > 0) {
if (n & 1) res *= a;
a *= a;
n >>= 1;
}
return res;
}
uint32_t get() const { return val; }
static constexpr int get_mod() { return mod; }
static constexpr pair<int, int> ntt_info() {
if (mod == 167772161) return {25, 17};
if (mod == 469762049) return {26, 30};
if (mod == 754974721) return {24, 362};
if (mod == 880803841) return {23, 211};
if (mod == 998244353) return {23, 31};
return {-1, -1};
}
};
template <int mod>
void rd(modint<mod> &x) {
uint32_t y;
cin >> y;
x = y;
}
template <int mod>
void wt(modint<mod> x) {
wt(x.val);
}
using mint = modint<998244353>;
// 高々1しか増やせない
// どのようにswapしても増やせないような数列の個数を数え上げる.
int main() {
INT(N, M);
VC(int, A, N);
vv(mint, dp, N, 4);
dp[0][0] = mint(1), dp[0][2] = mint(1);
FOR(i, 1, N) {
if (A[i - 1] < A[i]) {
dp[i][0] += mint(max(A[i] - A[i - 1], 0)) * dp[i - 1][2];
dp[i][1] += mint(A[i - 1]) * dp[i - 1][0] + mint(M - A[i]) * dp[i - 1][2];
dp[i][2] += mint(A[i - 1]) * dp[i - 1][0] + mint(M - A[i - 1]) * dp[i - 1][2];
if (i > 1) {
dp[i][0] += mint(max(min(A[i], A[i - 2]) - A[i - 1], 0)) * dp[i - 1][3];
dp[i][1] += mint(min(A[i - 1], A[i - 2])) * dp[i - 1][1] + mint(max(A[i - 2] - A[i], 0)) * dp[i - 1][3];
dp[i][2] += mint(min(A[i - 1], A[i - 2])) * dp[i - 1][1] + mint(max(A[i - 2] - A[i - 1], 0)) * dp[i - 1][3];
}
}
else if (A[i - 1] > A[i]) {
dp[i][0] += mint(A[i]) * dp[i - 1][0] + mint(M - A[i - 1]) * dp[i - 1][2];
dp[i][2] += mint(A[i]) * dp[i - 1][0] + mint(M - A[i - 1]) * dp[i - 1][2];
dp[i][3] += mint(A[i - 1] - A[i]) * dp[i - 1][0];
if (i > 1) {
dp[i][0] += mint(min(A[i], A[i - 2])) * dp[i - 1][1] + mint(max(A[i - 2] - A[i - 1], 0)) * dp[i - 1][3];
dp[i][2] += mint(min(A[i], A[i - 2])) * dp[i - 1][1] + mint(max(A[i - 2] - A[i - 1], 0)) * dp[i - 1][3];
dp[i][3] += mint(max(min(A[i - 1], A[i - 2]) - A[i], 0)) * dp[i - 1][1];
}
}
else {
dp[i][0] = mint(A[i - 1]) * dp[i - 1][0] + mint(M - A[i - 1]) * dp[i - 1][2];
dp[i][2] = mint(A[i - 1]) * dp[i - 1][0] + mint(M - A[i - 1]) * dp[i - 1][2];
if (i > 1) {
dp[i][0] += mint(min(A[i - 2], A[i - 1])) * dp[i - 1][1] + mint(max(A[i - 2] - A[i - 1], 0)) * dp[i - 1][3];
dp[i][2] += mint(min(A[i - 2], A[i - 1])) * dp[i - 1][1] + mint(max(A[i - 2] - A[i - 1], 0)) * dp[i - 1][3];
}
}
}
mint res = mint(A[N - 1]) * dp[N - 1][0] + mint(M - A[N - 1]) * dp[N - 1][2];
if (N >= 2) {
res += dp[N - 1][3] * mint(max(A[N - 2] - A[N - 1], 0)) + mint(min(A[N - 2], A[N - 1])) * dp[N - 1][1];
}
mint ans = mint(M).pow(N) - res;
FOR(i, N) {
ans += (mint(M).pow(N - 1)) * mint(M - A[i]);
}
print(ans);
}