#773788 (C++17) No.1975 Zigzag Sequence

• 問題: No.1975 Zigzag Sequence
• ユーザー: heno239
• 提出日時: 2022-06-25 13:21:19
• 言語: C++17 (gcc 12.3.0 + boost 1.83.0)
• 結果: AC
• 実行時間: 120 ms / 2,000 ms
• コード長: 5,887 bytes
• コンパイル時間: 2,343 ms
• コンパイル使用メモリ: 160,832 KB
• 実行使用メモリ: 13,936 KB
• 最終ジャッジ日時: 2024-11-14 09:59:58
• 合計ジャッジ時間: 6,917 ms
• ジャッジサーバーID （参考情報）: judge2 / judge1

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	20 ms; 11,848 KB
testcase_01	AC	21 ms; 11,724 KB
testcase_02	AC	21 ms; 11,852 KB
testcase_03	AC	29 ms; 11,848 KB
testcase_04	AC	24 ms; 11,844 KB
testcase_05	AC	106 ms; 13,128 KB
testcase_06	AC	77 ms; 12,620 KB
testcase_07	AC	30 ms; 11,980 KB
testcase_08	AC	76 ms; 12,492 KB
testcase_09	AC	103 ms; 13,252 KB
testcase_10	AC	79 ms; 12,616 KB
testcase_11	AC	85 ms; 12,748 KB
testcase_12	AC	35 ms; 11,976 KB
testcase_13	AC	20 ms; 11,848 KB
testcase_14	AC	20 ms; 11,716 KB
testcase_15	AC	21 ms; 11,720 KB
testcase_16	AC	20 ms; 11,716 KB
testcase_17	AC	20 ms; 11,720 KB
testcase_18	AC	69 ms; 13,160 KB
testcase_19	AC	69 ms; 13,164 KB
testcase_20	AC	84 ms; 13,256 KB
testcase_21	AC	83 ms; 13,260 KB
testcase_22	AC	94 ms; 13,928 KB
testcase_23	AC	95 ms; 13,936 KB
testcase_24	AC	104 ms; 13,936 KB
testcase_25	AC	102 ms; 13,808 KB
testcase_26	AC	111 ms; 13,132 KB
testcase_27	AC	120 ms; 13,420 KB
testcase_28	AC	102 ms; 13,932 KB
testcase_29	AC	102 ms; 13,936 KB
testcase_30	AC	102 ms; 13,804 KB
testcase_31	AC	102 ms; 13,804 KB
testcase_32	AC	70 ms; 13,164 KB
testcase_33	AC	70 ms; 13,036 KB
testcase_34	AC	111 ms; 13,192 KB
testcase_35	AC	111 ms; 13,316 KB

ソースコード

#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include<iostream>
#include<string>
#include<cstdio>
#include<vector>
#include<cmath>
#include<algorithm>
#include<functional>
#include<iomanip>
#include<queue>
#include<ciso646>
#include<random>
#include<map>
#include<set>
#include<bitset>
#include<stack>
#include<unordered_map>
#include<unordered_set>
#include<utility>
#include<cassert>
#include<complex>
#include<numeric>
#include<array>
#include<chrono>
using namespace std;

//#define int long long
typedef long long ll;

typedef unsigned long long ul;
typedef unsigned int ui;
//constexpr ll mod = 998244353;
constexpr ll mod = 1000000007;
const ll INF = mod * mod;
typedef pair<int, int>P;

#define rep(i,n) for(int i=0;i<n;i++)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define Rep(i,sta,n) for(int i=sta;i<n;i++)
#define rep1(i,n) for(int i=1;i<=n;i++)
#define per1(i,n) for(int i=n;i>=1;i--)
#define Rep1(i,sta,n) for(int i=sta;i<=n;i++)
#define all(v) (v).begin(),(v).end()
typedef pair<ll, ll> LP;

template<typename T>
void chmin(T& a, T b) {
	a = min(a, b);
}
template<typename T>
void chmax(T& a, T b) {
	a = max(a, b);
}
template<typename T>
void cinarray(vector<T>& v) {
	rep(i, v.size())cin >> v[i];
}
template<typename T>
void coutarray(vector<T>& v) {
	rep(i, v.size()) {
		if (i > 0)cout << " "; cout << v[i];
	}
	cout << "\n";
}
ll mod_pow(ll x, ll n, ll m = mod) {
	if (n < 0) {
		ll res = mod_pow(x, -n, m);
		return mod_pow(res, m - 2, m);
	}
	if (abs(x) >= m)x %= m;
	if (x < 0)x += m;
	//if (x == 0)return 0;
	ll res = 1;
	while (n) {
		if (n & 1)res = res * x % m;
		x = x * x % m; n >>= 1;
	}
	return res;
}
struct modint {
	int n;
	modint() :n(0) { ; }
	modint(ll m) {
		if (m < 0 || mod <= m) {
			m %= mod; if (m < 0)m += mod;
		}
		n = m;
	}
	operator int() { return n; }
};
bool operator==(modint a, modint b) { return a.n == b.n; }
bool operator<(modint a, modint b) { return a.n < b.n; }
modint operator+=(modint& a, modint b) { a.n += b.n; if (a.n >= mod)a.n -= mod; return a; }
modint operator-=(modint& a, modint b) { a.n -= b.n; if (a.n < 0)a.n += mod; return a; }
modint operator*=(modint& a, modint b) { a.n = ((ll)a.n * b.n) % mod; return a; }
modint operator+(modint a, modint b) { return a += b; }
modint operator-(modint a, modint b) { return a -= b; }
modint operator*(modint a, modint b) { return a *= b; }
modint operator^(modint a, ll n) {
	if (n == 0)return modint(1);
	modint res = (a * a) ^ (n / 2);
	if (n % 2)res = res * a;
	return res;
}

ll inv(ll a, ll p) {
	return (a == 1 ? 1 : (1 - p * inv(p % a, a)) / a + p);
}
modint operator/(modint a, modint b) { return a * modint(inv(b, mod)); }
modint operator/=(modint& a, modint b) { a = a / b; return a; }
const int max_n = 1 << 20;
modint fact[max_n], factinv[max_n];
void init_f() {
	fact[0] = modint(1);
	for (int i = 0; i < max_n - 1; i++) {
		fact[i + 1] = fact[i] * modint(i + 1);
	}
	factinv[max_n - 1] = modint(1) / fact[max_n - 1];
	for (int i = max_n - 2; i >= 0; i--) {
		factinv[i] = factinv[i + 1] * modint(i + 1);
	}
}
modint comb(int a, int b) {
	if (a < 0 || b < 0 || a < b)return 0;
	return fact[a] * factinv[b] * factinv[a - b];
}
modint combP(int a, int b) {
	if (a < 0 || b < 0 || a < b)return 0;
	return fact[a] * factinv[a - b];
}

ll gcd(ll a, ll b) {
	a = abs(a); b = abs(b);
	if (a < b)swap(a, b);
	while (b) {
		ll r = a % b; a = b; b = r;
	}
	return a;
}
typedef long double ld;
typedef pair<ld, ld> LDP;
const ld eps = 1e-8;
const ld pi = acosl(-1.0);
template<typename T>
void addv(vector<T>& v, int loc, T val) {
	if (loc >= v.size())v.resize(loc + 1, 0);
	v[loc] += val;
}
/*const int mn = 100005;
bool isp[mn];
vector<int> ps;
void init() {
	fill(isp + 2, isp + mn, true);
	for (int i = 2; i < mn; i++) {
		if (!isp[i])continue;
		ps.push_back(i);
		for (int j = 2 * i; j < mn; j += i) {
			isp[j] = false;
		}
	}
}*/

//[,val)
template<typename T>
auto prev_itr(set<T>& st, T val) {
	auto res = st.lower_bound(val);
	if (res == st.begin())return st.end();
	res--; return res;
}

//[val,)
template<typename T>
auto next_itr(set<T>& st, T val) {
	auto res = st.lower_bound(val);
	return res;
}
using mP = pair<modint, modint>;
mP operator+(mP a, mP b) {
	return { a.first + b.first,a.second + b.second };
}
mP operator+=(mP& a, mP b) {
	a = a + b; return a;
}
mP operator-(mP a, mP b) {
	return { a.first - b.first,a.second - b.second };
}
mP operator-=(mP& a, mP b) {
	a = a - b; return a;
}

mt19937 mt(time(0));

const string drul = "DRUL";
string senw = "SENW";
//DRUL,or SENW
int dx[4] = { 1,0,-1,0 };
int dy[4] = { 0,1,0,-1 };
//-----------------------------------------


template<typename T>
struct BIT {
private:
	vector<T> node; int n;
public:
	BIT(int n_) {
		n = n_; node.resize(n, 0);
	}
	//0-indexed
	void add(int a, T w) {
		for (int i = a; i < n; i |= i + 1)node[i] += w;
	}
	//[0,a)
	T sum(int a) {
		T ret = 0;
		for (int i = a - 1; i >= 0; i = (i & (i + 1)) - 1)ret += node[i];
		return ret;
	}
	//[a,b)
	T sum(int a, int b) {
		return sum(b) - sum(a);
	}
};

modint calc(vector<int> a) {
	int n = a.size();
	vector<int> va = a;
	sort(all(va));
	va.erase(unique(all(va)), va.end());
	rep(i, n) {
		a[i] = lower_bound(all(va), a[i]) - va.begin();
	}
	BIT<modint> btl(va.size());
	vector<modint> c(n, 1);
	rep(i, n) {
		modint val = btl.sum(0, a[i]);
		c[i] *= val;
		btl.add(a[i], mod_pow(2, i));
	}
	BIT<modint> btr(va.size());
	per(i, n) {
		modint val = btr.sum(0, a[i]);
		c[i] *= val;
		btr.add(a[i], mod_pow(2, n - 1 - i));
	}
	modint ans = 0;
	rep(i, n)ans += c[i];
	return ans;
}
void solve() {
	int n; cin >> n;
	vector<int> a(n);
	rep(i, n)cin >> a[i];
	modint ans = calc(a);
	rep(i, n)a[i] *= -1;
	ans += calc(a);
	cout << ans << "\n";
}

signed main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	//cout << fixed << setprecision(10);
	init_f();
	//init();
	//while(true)
	//expr();
	solve();
	return 0;
}