Submission #998581

#	Time	Username	Problem	Language	Result	Execution time	Memory
998581		steveonalex	Flooding Wall (BOI24_wall)	C++17	58 / 100	5059 ms	31688 KiB

Main

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
 
#define MASK(i) (1ULL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
#define block_of_code if(true)
 
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
ll gcd(ll a, ll b){return __gcd(a, b);}
 
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ll mask){return __builtin_popcountll(mask);}
int ctz(ull mask){return __builtin_ctzll(mask);}
int logOf(ull mask){return 63 - __builtin_clzll(mask);}
 
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}
 
template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }
 
template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }
 
template <class T>
    void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }
 
template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }


 
const int MOD = 1e9 + 7;
struct Modular{
    ll x;
    Modular(ll _x = 0){x = _x;}
    Modular& operator += (Modular y){
        x += y.x;
        if (x >= MOD) x -= MOD;
        return *this;
    }
    Modular operator + (Modular y) {
        Modular tmp = *this;
        return tmp += y;
    }
 
    Modular& operator -= (Modular y){
        x -= y.x;
        if (x < 0) x += MOD;
        return *this;
    }
    Modular operator - (Modular y) {
        Modular tmp = *this;
        return tmp -= y;
    }
 
    Modular& operator *= (Modular y){
        x *= y.x;
        if (x >= MOD) x %= MOD;
        return *this;
    }
    Modular operator * (Modular y) {
        Modular tmp = *this;
        return tmp *= y;
    }
 
    // use at your own risk
    bool operator == (Modular y){
        return x == y.x;
    }
    bool operator != (Modular y){
        return x != y.x;
    }
};
ostream& operator << (ostream& out, Modular x){
    out << x.x;
    return out;
}

const int N = 5e5 + 69;
array<int, 2> a[N], c[N];
array<Modular, 2> pref[N], suff[N];
Modular p2[N];

struct FenwickTree{
    int n;
    vector<Modular> a;

    FenwickTree(int _n){
        n = _n;
        a.resize(n + 1, 1);
    }

    void update(int i){
        while(i <= n){
            a[i] *= 2;
            i += LASTBIT(i);
        }
    }

    Modular get(int i){
        Modular ans = 1;
        while(i > 0){
            ans *= a[i];
            i -= LASTBIT(i);
        }
        return ans;
    }

    void reset(){
        a = vector<Modular>(n+1, 1);
    }
};

struct SegmentTree{
    struct Node{
        Modular val, lazy;
        Node(){
            val = 0;
            lazy = 1;
        }
    };
    int n;
    vector<Node> a;

    SegmentTree(int _n){
        n = _n;
        a.resize(n * 4 + 4);
    }

    void down(int id){
        Modular x = a[id].lazy;
        a[id * 2].val *= x; a[id * 2 + 1].val *= x;
        a[id * 2].lazy *= x; a[id * 2 + 1].lazy *= x;
        a[id].lazy = 1;
    }

    void add(int i, Modular val, int l, int r, int id){
        if (l == r){
            a[id].val += val;
            return;
        }
        if (a[id].lazy != 1) down(id);
        int mid = (l + r) >> 1;
        if (i <= mid) add(i, val, l, mid, id * 2);
        if (i > mid) add(i, val, mid + 1, r, id * 2 + 1);
        a[id].val = a[id * 2].val + a[id * 2 + 1].val;
    }

    void add(int i, Modular val){
        if (1 <= i && i <= n) add(i, val, 1, n, 1);
    }

    void mul(int u, int v, Modular val, int l, int r, int id){
        if (u <= l && r <= v){
            a[id].val *= val;
            a[id].lazy *= val;
            return;
        }
        if (a[id].lazy != 1) down(id);
        int mid = (l + r) >> 1;
        if (u <= mid) mul(u, v, val, l, mid, id * 2);
        if (v > mid) mul(u, v, val, mid + 1, r, id * 2 + 1);
        a[id].val = a[id * 2].val + a[id * 2 + 1].val;
    }

    void mul(int l, int r, Modular val){
        if (l <= r) mul(l, r, val, 1, n, 1);
    }

    Modular get(int u, int v, int l, int r, int id){
        if (u <= l && r <= v) return a[id].val;
        if (a[id].lazy != 1) down(id);
        int mid = (l + r) >> 1;
        Modular ans = 0;
        if (u <= mid) ans += get(u, v, l, mid, id * 2);
        if (v > mid) ans += get(u, v, mid + 1, r, id * 2 + 1);
        return ans;
    }

    Modular get(int l, int r){
        if (l > r) return 0;
        return get(l, r, 1, n, 1);
    }
};  

int main(void){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    int n; cin >> n;
    for(int j = 0; j<=1; ++j)
    for(int i = 0; i<n; ++i) cin >> a[i][j];
    for(int i = 0; i<n; ++i) sort(ALL(a[i]));

    p2[0] = 1;
    for(int i = 1; i<N; ++i) p2[i] = p2[i-1] * 2;

    Modular ans = 0;

    for(int i= 0; i<n; ++i){
        for(int u: a[i]) ans -= p2[n-1] * u;
    }

    vector<int> b;
    for(int i= 0; i<n; ++i)
        for(int j = 0; j<2; ++j) b.push_back(a[i][j]);
    remove_dup(b);

    for(int i = 0; i<n; ++i) for(int j = 0; j<2; ++j) c[i][j] = lower_bound(ALL(b), a[i][j]) - b.begin() + 1;

    int m = b.size();

    FenwickTree bit(m);
    int ma = 0;
    for(int i =0; i<n; ++i){
        for(int u = 0; u<=1; ++u){
            if (a[i][u] <= ma) continue;
            pref[i][u] = bit.get(c[i][u]);
        }
        bit.update(c[i][1] + 1);
        maximize(ma, a[i][0]);
    }
    bit.reset();
    ma = 0;
    for(int i = n-1; i>=0; --i) {
        for(int u = 0; u<=1; ++u){
            if (a[i][u] <= ma) continue;
            suff[i][u] = bit.get(c[i][u]);
        }
        bit.update(c[i][1] + 1);
        maximize(ma, a[i][0]);
    }

    for(int iteration = 0; iteration <= 1; ++iteration){
        SegmentTree slope(m), sum(m);

        for(int i = 0; i<n; ++i){
            for(int _u = 0; _u <= 1; ++_u){
                ans += (slope.get(1, c[i][_u] - 1) * i - sum.get(1, c[i][_u] - 1)) * p2[n-1-i];
            }

            slope.mul(1, c[i][0] - 1, 0); sum.mul(1, c[i][0] - 1, 0);
            slope.mul(c[i][1], m, 2); sum.mul(c[i][1], m, 2);

            for(int _u = 0; _u <= 1; ++_u){
                int u = a[i][_u];
                Modular cu = pref[i][_u];
                if (cu == 0) continue;
                slope.add(c[i][_u], cu * u);
                sum.add(c[i][_u], cu * u * i);

            }
        }

        reverse(a, a + n);
        reverse(c, c + n);
        reverse(pref, pref + n);
        reverse(suff, suff + n);
        for(int i = 0; i<n; ++i) swap(pref[i], suff[i]);
    }


    for(int i = 0; i<n; ++i) {
        for(int u = 0; u <= 1; ++u) ans += pref[i][u] * suff[i][u] * a[i][u];
    }
    for(int i = 0; i<n; ++i) for(int u = 0; u <= 1; ++u){
        Modular mul = 1;
        for(int j = i + 1; j<n; ++j){
            for(int v = 0; v <= 1; ++v) if (a[i][u] == a[j][v]){
                ans += pref[i][u] * suff[j][v] * mul * a[i][u] * (j - i + 1);
            }

            int cnt= 0;
            for(int v: a[j]) cnt += v <= a[i][u];
            mul *= cnt; 
        }
    }

    cout << ans << "\n";


    return 0;
}

• Subtask 1: 8 / 8
• Subtask 2: 17 / 17
• Subtask 3: 19 / 19
• Subtask 4: 14 / 14
• Subtask 5: 0 / 12
• Subtask 6: 0 / 30