Submission #1164205

#	Time	Username	Problem	Language	Result	Execution time	Memory
1164205		cjtsai	Flooding Wall (BOI24_wall)	C++20	12 / 100	43 ms	15944 KiB

Main

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pii pair<int,int>
#define pb push_back
#define all(x) x.begin(),x.end()
#define ff first
#define ss second

const int mod=1e9+7;

signed main(){
	ios_base::sync_with_stdio(false);cin.tie(0);
	int n;cin>>n;
	vector<int> a(n), b(n);
	for(int i=0; i<n; i++) cin>>a[i];
	for(int i=0; i<n; i++) cin>>b[i];
	vector<int> pre(n+10, 1);
	for(int i=1; i<n+5; i++) pre[i]=pre[i-1]*2%mod;
	int twos=0;
	vector<int> tp(n);
	for(int i=0; i<n; i++){
		tp[i]=twos;
		if(a[i]==2) twos++;
		if(b[i]==2) twos++;
	}
	int ans=0;
	twos=0;
	for(int i=n-1; i>=0; i--){
		if(a[i]==1&&b[i]==1){
			ans+=2*(pre[twos]-1)*(pre[tp[i]]-1);
			ans%=mod;
		}else if(a[i]==2&&b[i]==2){
			twos+=2;
		}else{
			ans+=(pre[twos]-1)*(pre[tp[i]]-1);
			ans%=mod;
			twos++;
		}
	}
	cout<<ans;

}

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