Submission #1997404


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#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=a;i<b;i++)
#define rrep(i,a,b) for(int i=a;i>=b;i--)
#define fore(i,a) for(auto &i:a)
#define all(x) (x).begin(),(x).end()
#pragma GCC optimize ("-O3")
using namespace std; void _main(); int main() { cin.tie(0); ios::sync_with_stdio(false); _main(); }
typedef long long ll; const int inf = INT_MAX / 2; const ll infl = 1LL << 60;
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a = b; return 1; } return 0; }
//---------------------------------------------------------------------------------------------------
template<class V> struct BIT { BIT() {}  // [L, R)
    int NV;vector<V> bit;BIT(int n){init(n);}void init(int n){NV=1;while(NV<n)NV*=2;bit.resize(NV);}
    V operator[](int e) { V s = 0; e++; while (e) s += bit[e - 1], e -= e&-e; return s; }
    void add(int e, V v) { e++; while (e <= NV) bit[e - 1] += v, e += e&-e; }
    int lower_bound(V val) { V tv = 0; int i, ent = 0; for (i = NV - 1; i >= 0; i--)
        if(tv+bit[ent+(1<<i)-1]<=val)tv+=bit[ent+(1<<i)-1],ent += (1 << i);return ent;}
    V get(int L, int R) {assert(0 <= L); assert(R <= NV); assert(L <= R);
        V res = 0; if(R) res += operator[](R - 1); if (L) res -= operator[](L - 1);return res;}
    void clear() { bit.clear(); }};
template<int MOD> struct ModInt {
    static const int Mod = MOD; unsigned x; ModInt() : x(0) { }
    ModInt(signed sig) { x = sig < 0 ? sig % MOD + MOD : sig % MOD; }
    ModInt(signed long long sig) { x = sig < 0 ? sig % MOD + MOD : sig % MOD; }
    int get() const { return (int)x; }
    ModInt &operator+=(ModInt that) { if ((x += that.x) >= MOD) x -= MOD; return *this; }
    ModInt &operator-=(ModInt that) { if ((x += MOD - that.x) >= MOD) x -= MOD; return *this; }
    ModInt &operator*=(ModInt that) { x = (unsigned long long)x * that.x % MOD; return *this; }
    ModInt &operator/=(ModInt that) { return *this *= that.inverse(); }
    ModInt operator+(ModInt that) const { return ModInt(*this) += that; }
    ModInt operator-(ModInt that) const { return ModInt(*this) -= that; }
    ModInt operator*(ModInt that) const { return ModInt(*this) *= that; }
    ModInt operator/(ModInt that) const { return ModInt(*this) /= that; }
    ModInt inverse() const { long long a = x, b = MOD, u = 1, v = 0;
        while (b) { long long t = a / b; a -= t * b; std::swap(a, b); u -= t * v; std::swap(u, v); }
        return ModInt(u); }
    bool operator==(ModInt that) const { return x == that.x; }
    bool operator!=(ModInt that) const { return x != that.x; }
    ModInt operator-() const { ModInt t; t.x = x == 0 ? 0 : Mod - x; return t; }
};
template<int MOD> ostream& operator<<(ostream& st, const ModInt<MOD> a) { st << a.get(); return st; };
template<int MOD> ModInt<MOD> operator^(ModInt<MOD> a, unsigned long long k) {
    ModInt<MOD> r = 1; while (k) { if (k & 1) r *= a; a *= a; k >>= 1; } return r; }
typedef ModInt<1000000007> mint;
/*---------------------------------------------------------------------------------------------------
            ∧_∧  
      ∧_∧  (´<_` )  Welcome to My Coding Space!
     ( ´_ゝ`) /  ⌒i     
    /   \     | |     
    /   / ̄ ̄ ̄ ̄/  |  
  __(__ニつ/     _/ .| .|____  
     \/____/ (u ⊃  
---------------------------------------------------------------------------------------------------*/



int N;
vector<pair<int, int>> v;
BIT<mint> bit;
//---------------------------------------------------------------------------------------------------
void _main() {
    cin >> N;
    rep(i, 0, N) {
        int a, b; cin >> a >> b;
        if (a < b) swap(a, b);
        v.push_back({ a, b });
    }
    sort(v.begin(), v.end());
    bit.init(N * 2 + 1);

    mint po = mint(2) ^ (N - 2);
    mint ans = 0;
    rep(i, 0, N) {
        int a = v[i].first;
        int b = v[i].second;
        // a >= b
        
        ans += bit.get(b + 1, N * 2 + 1) * po;
        
        bit.add(a, 1);
        bit.add(b, 1);
    }
    cout << ans << endl;
}

Submission Info

Submission Time
Task D - Chaos of the Snuke World
User hamayanhamayan
Language C++14 (GCC 5.4.1)
Score 800
Code Size 4295 Byte
Status AC
Exec Time 38 ms
Memory 2164 KB

Judge Result

Set Name Sample All
Score / Max Score 0 / 0 800 / 800
Status
AC × 2
AC × 31
Set Name Test Cases
Sample s1.txt, s2.txt
All 01.txt, 02.txt, 03.txt, 04.txt, 05.txt, 06.txt, 07.txt, 08.txt, 09.txt, 10.txt, 11.txt, 12.txt, 13.txt, 14.txt, 15.txt, 16.txt, 17.txt, 18.txt, 19.txt, 20.txt, 21.txt, 22.txt, 23.txt, 24.txt, 25.txt, 26.txt, 27.txt, 28.txt, 29.txt, s1.txt, s2.txt
Case Name Status Exec Time Memory
01.txt AC 37 ms 2164 KB
02.txt AC 37 ms 2164 KB
03.txt AC 37 ms 2164 KB
04.txt AC 37 ms 2164 KB
05.txt AC 37 ms 2164 KB
06.txt AC 37 ms 2164 KB
07.txt AC 37 ms 2164 KB
08.txt AC 37 ms 2164 KB
09.txt AC 37 ms 2164 KB
10.txt AC 37 ms 2164 KB
11.txt AC 38 ms 2164 KB
12.txt AC 37 ms 2164 KB
13.txt AC 38 ms 2164 KB
14.txt AC 38 ms 2164 KB
15.txt AC 27 ms 2164 KB
16.txt AC 30 ms 2164 KB
17.txt AC 29 ms 2164 KB
18.txt AC 28 ms 2164 KB
19.txt AC 29 ms 2164 KB
20.txt AC 29 ms 2164 KB
21.txt AC 28 ms 2164 KB
22.txt AC 29 ms 2164 KB
23.txt AC 29 ms 2164 KB
24.txt AC 36 ms 2164 KB
25.txt AC 1 ms 256 KB
26.txt AC 1 ms 256 KB
27.txt AC 1 ms 256 KB
28.txt AC 1 ms 256 KB
29.txt AC 1 ms 256 KB
s1.txt AC 1 ms 256 KB
s2.txt AC 1 ms 256 KB