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Submission #463419

# Submission time Handle Problem Language Result Execution time Memory
463419 2021-08-11T06:22:22 Z amunduzbaev Exam (eJOI20_exam) C++14
55 / 100
 112 ms 1112 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);
	if(n <= 205){
		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--){
				//~ int mx = -1e9;
				//~ for(int l=r;l>=e;l--){
					//~ mx = max((l ? - cnt[l-1] + dp[l-1] : 0), mx);
					//~ mx = max(mx, (l ? - cnt[l-1] + dp[l-1] : 0));
				//~ }
				
				dp[r] = max(dp[r], cnt[r] + pref[r]);
			}
		}
		
		for(int i=0;i<n;i++) res = max(res, dp[i]);
		cout<<res<<"\n";
	} else {
		int res;
		for(int i=0;i<n;i++){
			int r = i, l = i;
			while(r + 1 < n && a[r + 1] <= a[i]) r++;
			while(l > 0 && a[l - 1] <= a[l]) l--;
			vector<int> cnt(n), pref(n);
			for(int j=0;j<n;j++){
				if(j) cnt[j] = cnt[j-1];
				cnt[j] += (b[j] == a[i]);
			}
 
			for(int i=l;i<=r;i++){
				if(i) pref[i] = pref[i-1];
				pref[i] = max(pref[i], (i ? dp[i - 1] - cnt[i - 1] : 0));
			}
 
			for(int j=l;j<=r;j++){
				dp[j] = max(dp[j], cnt[j] + pref[j]);
			}
		}
 
		for(int i=0;i<n;i++) res = max(res, dp[i]);
		cout<<res<<"\n";
	}
}
 
void solve2(int n, vector<int>& a, vector<int>& b){
	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";
}
 
void solve(){
	int n; cin>>n;
	vector<int> a(n), b(n);
	for(auto& x : a) cin>>x;
	for(auto& x : b) cin>>x;
	
	int mx = 0, mn = 1e9;
	for(auto x : b) mx = max(mx, x), mn = min(mn, x);
	if(mx == mn){
		solve2(n, a, b);
		return;
	}
	
	if(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();
}

Compilation message

exam.cpp: In function 'void solve1(int, std::vector<int>&, std::vector<int>&)':
exam.cpp:41:7: warning: 'res' may be used uninitialized in this function [-Wmaybe-uninitialized]
   41 |   int res;
      |       ^~~

Subtask #1
14.0 / 14.0

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

Subtask #2
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 5 ms 460 KB Output is correct
3 Correct 20 ms 1032 KB Output is correct
4 Correct 15 ms 1112 KB Output is correct
5 Correct 27 ms 1100 KB Output is correct
6 Correct 15 ms 1108 KB Output is correct
7 Correct 15 ms 1108 KB Output is correct
8 Correct 25 ms 1112 KB Output is correct

Subtask #3
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 2 ms 204 KB Output is correct
3 Correct 19 ms 332 KB Output is correct
4 Correct 103 ms 388 KB Output is correct
5 Correct 110 ms 388 KB Output is correct
6 Correct 112 ms 384 KB Output is correct

Subtask #4
0 / 23.0

# Verdict Execution time Memory Grader output
1 Incorrect 40 ms 332 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 1 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 0 ms 204 KB Output is correct
9 Correct 1 ms 204 KB Output is correct
10 Correct 1 ms 204 KB Output is correct
11 Correct 1 ms 204 KB Output is correct
12 Correct 1 ms 204 KB Output is correct
13 Correct 1 ms 204 KB Output is correct
14 Correct 1 ms 204 KB Output is correct

Subtask #6
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 1 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 2 ms 204 KB Output is correct
9 Correct 19 ms 332 KB Output is correct
10 Correct 103 ms 388 KB Output is correct
11 Correct 110 ms 388 KB Output is correct
12 Correct 112 ms 384 KB Output is correct
13 Correct 1 ms 204 KB Output is correct
14 Correct 0 ms 204 KB Output is correct
15 Correct 1 ms 204 KB Output is correct
16 Correct 1 ms 204 KB Output is correct
17 Correct 1 ms 204 KB Output is correct
18 Correct 1 ms 204 KB Output is correct
19 Correct 1 ms 204 KB Output is correct
20 Correct 1 ms 204 KB Output is correct
21 Correct 1 ms 204 KB Output is correct
22 Incorrect 2 ms 332 KB Output isn't correct
23 Halted 0 ms 0 KB -