Submission #833229

#	Time	Username	Problem	Language	Result	Execution time	Memory
833229		vjudge1	Exam (eJOI20_exam)	C++17	0 / 100	50 ms	73292 KiB

exam

#include<bits/stdc++.h>
using namespace std;
#define endl '\n'
#define ll long long
int n;
int a[100005], b[100005];
int memo[3000][3000];
int c[3000][3000];

int f(int last, int now){
//	cout<<last<<' '<<now<<endl;
	if(now > n) return 0;
	int &ret = memo[last][now];
	if(ret != -1) return ret;
	
	int mx = -1;
	for(int i=last; i<=now; i++){
		mx = max(a[i], mx);
	}
	int cnt = 0;
	for(int i=last; i<=now; i++){
		if(mx == b[i]) cnt++;
	}
	c[last][now] = cnt;
	ret = cnt;
	mx = 0;
	for(int i=now+1; i<=n; i++){
		mx = max(mx, f(now+1, i));
	}
	ret += mx;
	return ret;
}

int main(){
//	ios::sync_with_stdio(0); cin.tie(0);
	cin>>n;
	bool sub2 = true;
	for(int i=1; i<=n; i++) cin>>a[i];
	for(int i=1; i<=n; i++){
		cin>>b[i];
		if(i > 1 && b[i] != b[1]) sub2 = false;
	}
	for(int i=1; i<=n; i++){
		for(int j=1; j<=n; j++) memo[i][j] = -1;
	}
	for(int i=1; i<=n; i++){
		for(int j=1; j<=n; j++) c[i][j] = -1;
	}
	if(n <= 10){
		int ans = -1;
		for(int i=1; i<=n; i++){
			ans = max(ans, f(1, i));
		}
		cout<<ans<<endl;
	}
	else if(sub2){
//		cout<<"NYALA\n";
		vector<int> id;
		int on[n+5];
		memset(on, 0, sizeof(on));
		for(int i=1; i<=n; i++){
			if(a[i] == b[i]) id.push_back(i);
		}
		for(auto z: id){
			if(!on[z]){
				on[z] = 1;
				int x = z+1;
				while(x <= n && a[x] < a[z]){
					on[x] = 1;
					x++;
				}
				x = z-1;
				while(x >= 1 && a[x] < a[z]){
					on[x] = 1;
					x++;
				}
			}
		}	
		int cnt = 0;
		for(int i=1; i<=n; i++){
			if(on[i]) cnt++;
		}
		cout<<cnt<<endl;
	}
	return 0;
}

• Subtask 1: 0 / 14
• Subtask 2: 0 / 12
• Subtask 3: 0 / 13
• Subtask 4: 0 / 23
• Subtask 5: 0 / 16
• Subtask 6: 0 / 22