結果
問題 | No.1294 マウンテン数列 |
ユーザー |
|
提出日時 | 2020-11-20 22:48:56 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 708 ms / 2,000 ms |
コード長 | 5,520 bytes |
コンパイル時間 | 2,340 ms |
コンパイル使用メモリ | 198,408 KB |
最終ジャッジ日時 | 2025-01-16 02:53:44 |
ジャッジサーバーID (参考情報) |
judge2 / judge1 |
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ファイルパターン | 結果 |
---|---|
other | AC * 17 |
ソースコード
//@formatter:off#include<bits/stdc++.h>#define rep(i,n) for (int i = 0; i < int(n); ++i)#define rrep(i,n) for (int i = int(n)-1; i >= 0; i--)#define rep2(i,s,n) for (int i = int(s); i < int(n); ++i)#define all(a) a.begin(),a.end()#define rall(a) a.rbegin(),a.rend()#define pb push_back#define eb emplace_back#define vi vector<int>#define vvi vector<vector<int>>#define vl vector<ll>#define vvl vector<vector<ll>>#define vd vector<double>#define vvd vector<vector<double>>#define vs vector<string>#define vc vector<char>#define vvc vector<vector<char>>#define vb vector<bool>#define vvb vector<vector<bool>>#define vp vector<P>#define vvp vector<vector<P>>using namespace std;using ll = long long;using P = pair<int,int>;using LP = pair<ll,ll>;template<class S,class T> istream& operator>>(istream &is,pair<S,T> &p) { return is >> p.first >> p.second; }template<class S,class T> ostream& operator<<(ostream &os,const pair<S,T> &p) { return os<<'{'<<p.first<<","<<p.second<<'}'; }template<class T> istream& operator>>(istream &is,vector<T> &v) { for(T &t:v){is>>t;} return is; }template<class T> ostream& operator<<(ostream &os,const vector<T> &v) { os<<'[';rep(i,v.size())os<<v[i]<<(i==int(v.size()-1)?"":","); return os<<']';}void Yes(bool b) { cout << (b ? "Yes" : "No") << '\n'; }void YES(bool b) { cout << (b ? "YES" : "NO") << '\n'; }template<class T> bool chmin(T& a,T b) {if(a > b){a = b; return true;} return false;}template<class T> bool chmax(T& a,T b) {if(a < b){a = b; return true;} return false;}const int inf = 1001001001;const ll linf = 1001001001001001001;//@formatter:on//constexpr int mod = 1000000007;constexpr int mod = 998244353;struct mint {ll x;constexpr mint(ll x = 0) : x((x % mod + mod) % mod) {}constexpr mint operator-() const { return mint(-x); }constexpr mint &operator+=(const mint &a) {if ((x += a.x) >= mod) x -= mod;return *this;}constexpr mint &operator++() { return *this += mint(1); }constexpr mint &operator-=(const mint &a) {if ((x += mod - a.x) >= mod) x -= mod;return *this;}constexpr mint &operator--() { return *this -= mint(1); }constexpr mint &operator*=(const mint &a) {(x *= a.x) %= mod;return *this;}constexpr mint operator+(const mint &a) const {mint res(*this);return res += a;}constexpr mint operator-(const mint &a) const {mint res(*this);return res -= a;}constexpr mint operator*(const mint &a) const {mint res(*this);return res *= a;}constexpr mint pow(ll t) const {mint res = mint(1), a(*this);while (t > 0) {if (t & 1) res *= a;t >>= 1;a *= a;}return res;}// for prime modconstexpr mint inv() const { return pow(mod - 2); }constexpr mint &operator/=(const mint &a) { return *this *= a.inv(); }constexpr mint operator/(const mint &a) const {mint res(*this);return res /= a;}};ostream &operator<<(ostream &os, const mint &a) { return os << a.x; }bool operator==(const mint &a, const mint &b) { return a.x == b.x; }bool operator!=(const mint &a, const mint &b) { return a.x != b.x; }template<class Monoid>class segtree {using T = typename Monoid::value_type;int n;vector<T> val;public:constexpr segtree(int _n) {n = 1;while (n < _n) n *= 2;val = vector<T>(2 * n, Monoid::identity);}constexpr segtree(vector<T> init) {int _n = init.size();n = 1;while (n < _n) n *= 2;val = vector<T>(2 * n, Monoid::identity);rep(i, _n) val[i + n] = init[i];rrep(i, n) val[i] = Monoid::operate(val[i * 2], val[i * 2 + 1]);}// segment [l,r)T fold(int l, int r) {l += n, r += n;T fold_l = Monoid::identity;T fold_r = Monoid::identity;while (l < r) {if (l & 1) fold_l = Monoid::operate(fold_l, val[l++]);if (r & 1) fold_r = Monoid::operate(val[--r], fold_r);l >>= 1, r >>= 1;}return Monoid::operate(fold_l, fold_r);}template<class F>void update(int i, const F &f) {i += n;val[i] = f(val[i]);while (i > 1) {i >>= 1;val[i] = Monoid::operate(val[i * 2], val[i * 2 + 1]);}}};class Node {public:using value_type = mint;value_type value;Node(value_type value) : value(value) {}static constexpr value_type identity = 0;static constexpr value_type operate(const value_type &l, const value_type &r) {return l + r;}};int main() {ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);int n;cin >> n;vi a(n);cin >> a;int mx = 0;rep(i, n - 1) chmax(mx, a[i + 1] - a[i]);mint ans = 0;mint pre = 0;rep2(i, mx, 2500) {segtree<Node> st(n);st.update(n - 1, [](auto) { return 1; });rrep(j, n - 2) {auto it = upper_bound(all(a), a[j] + i);mint sum = st.fold(j + 2, it - a.begin());st.update(j + 1, [&](auto) { return sum; });}ans += (st.fold(1, n) - pre) * 2 * i;pre = st.fold(1, n);}cout << ans << endl;}