Submission #1062073

#	Time	Username	Problem	Language	Result	Execution time	Memory
1062073		Jarif_Rahman	Flooding Wall (BOI24_wall)	C++17	48 / 100	390 ms	1048576 KiB

Main

#include <bits/stdc++.h>
#define pb push_back
#define f first
#define sc second
using namespace std;
typedef long long int ll;
typedef string str;

const ll md = 1e9+7;
const int N = 5e5+5;
ll pw2[N];

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    pw2[0] = 1;
    for(int i = 1; i < N; i++) pw2[i] = (pw2[i-1]*2)%md;

    int n; cin >> n;
    vector<int> A(n), B(n);
    int m = 0;
    for(int &x: A) cin >> x, m = max(m, x);
    for(int &x: B) cin >> x, m = max(m, x);
    for(int i = 0; i < n; i++) if(A[i] > B[i]) swap(A[i], B[i]);

    m++;
    vector<int> cmnl(m, 0), cmxl(m, 0), cmnr(m, 0), cmxr(m, 0);
    for(int i = 0; i < n; i++) cmnr[A[i]]++, cmxr[B[i]]++;

    ll ans = 0;
    for(int i = 0; i+1 < n; i++){
        cmnr[A[i]]--, cmxr[B[i]]--;
        int xl = 0, yl = 0, xr = 0, yr = 0;
        for(int j = m-1; j > A[i]; j--){
            xl+=cmnl[j], yl+=cmxl[j], xr+=cmnr[j], yr+=cmxr[j];
            ll cur = 2;
            if(j <= B[i]) cur = 1;

            if(xl > 0) cur*=pw2[i], cur%=md;
            else cur*=(pw2[i-yl]*(pw2[yl]-1))%md, cur%=md;

            if(xr > 0) cur*=pw2[n-i-1], cur%=md;
            else cur*=(pw2[n-i-1-yr]*(pw2[yr]-1))%md, cur%=md;

            ans+=cur, ans%=md;
        }
        cmnl[A[i]]++, cmxl[B[i]]++;
    }

    cout << ans << "\n";
}

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