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Submission #463523

# Submission time Handle Problem Language Result Execution time Memory
463523 2021-08-11T09:42:24 Z amunduzbaev Exam (eJOI20_exam) C++14
48 / 100
 171 ms 10860 KB 
#include "bits/stdc++.h"
using namespace std;
 
//~ #define int long long
 
void solve1(int n, vector<int>& a, vector<int>& b){
	vector<int> dp(n);
	int res = 0;
	for(int i=0;i<n;i++){
		int s = i, e = i;
		while(s + 1 < n && a[s + 1] <= a[i]) s++;
		while(e && a[e - 1] <= a[i]) e--;

		vector<int> cnt(n);
		for(int j=0;j<n;j++){
			if(j) cnt[j] = cnt[j-1];
			cnt[j] += (b[j] == a[i]);
		}

		vector<int> pref(n, -1e9);
		for(int j=e;j<n;j++){
			if(j) pref[j] = pref[j-1];
			pref[j] = max(pref[j], (j ? - cnt[j-1] + dp[j-1] : 0));
		}

		for(int r=s;r>=e;r--){
			dp[r] = max(dp[r], cnt[r] + pref[r]);
		}
	}
	
	for(int i=0;i<n;i++) res = max(res, dp[i]);
	cout<<res<<"\n";
}

struct ST{
	vector<int> tree;
	int n;
	ST(int n) :n(n) {
		tree.resize(4 * n);
	}
	
	void sett(int i, int v, int lx, int rx, int x){
		if(lx == rx){
			tree[x] = v;
			return;
		}
		
		int m = (lx + rx)>>1;
		if(i <= m) sett(i, v, lx, m, x<<1);
		else sett(i, v, m+1, rx, x<<1|1);
		
		tree[x] = max(tree[x<<1], tree[x<<1|1]);
	}
	
	void sett(int i, int v){
		sett(i, v, 0, n, 1);
	}
	
	int get(int l, int r, int lx, int rx, int x){
		if(lx > r || rx < l) return 0;
		if(lx >= l && rx <= r) return tree[x];
		int m = (lx + rx)>>1;
		return max(get(l, r, lx, m, x<<1), get(l, r, m+1, rx, x<<1|1));
	}
	
	int get(int l, int r){
		if(r < l) return 0;
		return get(l, r, 0, n, 1);
	}
}; 
 
void solve2(int n, vector<int>& a, vector<int>& b){
	int mn = 1e9, mx = 0;
	for(auto x : b) mn = min(mn, x), mx = max(mx, x);
	if(mx == mn){
		int last = 0, cnt = 0, res = 0;
		for(int i=0;i<n;i++){
			if(a[i] > b[0]){
				if(cnt){
					res += (i - last);
				}
				
				cnt = 0, last = i + 1;
			} else {
				cnt |= (a[i] == b[i]);
			}
		} if(cnt){
			res += (n - last);
		}
		
		cout<<res<<"\n";
		return;
	}
	
	//~ I DONT KNOW HOW TO SOLVE
	
	ST tree(n), lazy(n);
	
	map<int, int> pp;
	for(int i=0;i<n;i++) pp[a[i]] = i, lazy.sett(i, a[i]);
	
	for(int i=0;i<n;i++){
		if(pp.count(b[i])){
			int l = i, r = pp[b[i]];
			if(lazy.get(min(l, r), max(l, r)) > b[i]) continue;
			tree.sett(r, tree.get(0, r) + 1);
		} 
		
		//~ for(int i=0;i<n;i++) cout<<tree.get(i, i)<<" ";
		//~ cout<<"\n";
	}
	
	cout<<tree.get(0, n)<<"\n";
}

/*

3
2 1 0
2 2 1

*/
 
void solve(){
	int n; cin>>n;
	vector<int> a(n), b(n);
	for(auto& x : a) cin>>x;
	for(auto& x : b) cin>>x;

	if(n == -1 && n <= 5005){
		solve1(n, a, b);
	} else {
		solve2(n, a, b);
	}
}
 
/*
 
3
1 2 3
2 2 2
 
*/
 
signed main(){
	ios_base::sync_with_stdio(0); cin.tie(0);
	int t = 1;
	//~ cin>>t;
	while(t--) solve();
}

Subtask #1
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Incorrect 0 ms 204 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #2
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 7 ms 460 KB Output is correct
3 Correct 22 ms 1032 KB Output is correct
4 Correct 14 ms 1100 KB Output is correct
5 Correct 31 ms 1100 KB Output is correct
6 Correct 15 ms 1104 KB Output is correct
7 Correct 16 ms 1100 KB Output is correct
8 Correct 25 ms 1108 KB Output is correct

Subtask #3
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 2 ms 460 KB Output is correct
4 Correct 5 ms 716 KB Output is correct
5 Correct 6 ms 744 KB Output is correct
6 Correct 6 ms 744 KB Output is correct

Subtask #4
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 716 KB Output is correct
2 Correct 49 ms 3708 KB Output is correct
3 Correct 171 ms 10072 KB Output is correct
4 Correct 153 ms 10852 KB Output is correct
5 Correct 161 ms 10816 KB Output is correct
6 Correct 146 ms 10188 KB Output is correct
7 Correct 144 ms 10860 KB Output is correct
8 Correct 136 ms 10088 KB Output is correct
9 Correct 138 ms 10040 KB Output is correct
10 Correct 109 ms 10176 KB Output is correct

Subtask #5
0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Incorrect 0 ms 204 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #6
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Incorrect 0 ms 204 KB Output isn't correct
3 Halted 0 ms 0 KB -