Submission #832374

#	Time	Username	Problem	Language	Result	Execution time	Memory
832374		vjudge1	Exam (eJOI20_exam)	C++14	25 / 100	378 ms	99156 KiB

exam

#include<bits/stdc++.h>

#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
using namespace std;

#define ll long long
#define rep(i,n,N) for(int i = n; i<=N; ++i)
#define rap(i,n,N) for(int i = n; i>=N; --i)
#define For(i,n,N) for(int i = n; i< N; ++i)
#define endl '\n'
#define pb push_back
#define all(x) x.begin(),x.end()
#define mems(x,y) memset(x,y,sizeof x)
#define ari(x) array<int,x>
#define pll pair<ll,ll>
#define pii pair<int,int>
#define fi first
#define se second
const int MAX = 1e5 + 5;
mt19937 rng(time(NULL));

int n,x[MAX],y[MAX],cnt,dp[5005][5005];
vector<int> v,a,b;
bool vis[MAX],gg;

int f(int nw,int val){
	val = max(nw, val);
	if(val>n || nw>n)return 0;
	int &ret = dp[nw][val];
	if(ret!=-1)return ret;
	return ret = max(f(nw+1,val) + (y[nw]==val), f(nw, val+1));
}

int main(){
	ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
	cin>>n;
	rep(i,1,n)cin>>x[i], v.pb(x[i]);
	sort(all(v));
	v.erase(unique(all(v)), v.end());
	rep(i,1,n)x[i] = upper_bound(all(v), x[i]) - v.begin();
	auto it = v.begin();
	rep(i,1,n){
		cin>>y[i];
		it = lower_bound(all(v), y[i]);
		y[i] = it==v.end() || *it!=y[i] ? 0 : it-v.begin()+1;
	}
	
//	cout<<"____\n";
//	rep(i,1,n)cout<<x[i]<<" "; cout<<endl;
//	rep(i,1,n)cout<<y[i]<<" "; cout<<endl;
	
	x[0] = x[n+1] = v.size()+1;
	
	bool tc2 = 1;
	rep(i,2,n)if(y[i]!=y[i-1])tc2 = 0;
	if(tc2){
		gg = 0;
		rep(i,1,n){
			if(x[i]==y[i])gg = 1;
			else if(x[i]>y[i])gg = 0;
			vis[i]|= gg;
		}
		gg = 0;
		rap(i,n,1){
			if(x[i]==y[i])gg = 1;
			else if(x[i]>y[i])gg = 0;
			vis[i]|= gg;
			cnt+= vis[i];
		}
		cout<<cnt<<endl;
		return 0;
	}
	
	bool tc3 = 1;
	rep(i,1,n)if(x[i]!=i)tc3 = 0;
	if(tc3){
		mems(dp, -1);
		cout<<f(1,1)<<endl;
		return 0;
	}
	return 0;
}

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