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Submission #463420

# Submission time Handle Problem Language Result Execution time Memory
463420 2021-08-11T06:22:45 Z amunduzbaev Exam (eJOI20_exam) C++14
77 / 100
 188 ms 1400 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 <= 5005){
		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 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 0 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 468 KB Output is correct
3 Correct 18 ms 1032 KB Output is correct
4 Correct 14 ms 1104 KB Output is correct
5 Correct 27 ms 1100 KB Output is correct
6 Correct 15 ms 1108 KB Output is correct
7 Correct 16 ms 1112 KB Output is correct
8 Correct 27 ms 1100 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 30 ms 332 KB Output is correct
4 Correct 182 ms 388 KB Output is correct
5 Correct 184 ms 332 KB Output is correct
6 Correct 188 ms 332 KB Output is correct

Subtask #4
0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 111 ms 332 KB Output is correct
2 Incorrect 11 ms 1400 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #5
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 0 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 0 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
22.0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 0 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 30 ms 332 KB Output is correct
10 Correct 182 ms 388 KB Output is correct
11 Correct 184 ms 332 KB Output is correct
12 Correct 188 ms 332 KB Output is correct
13 Correct 0 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 Correct 5 ms 332 KB Output is correct
23 Correct 2 ms 332 KB Output is correct
24 Correct 144 ms 480 KB Output is correct
25 Correct 115 ms 488 KB Output is correct
26 Correct 110 ms 424 KB Output is correct
27 Correct 110 ms 420 KB Output is correct
28 Correct 112 ms 580 KB Output is correct
29 Correct 183 ms 432 KB Output is correct
30 Correct 134 ms 460 KB Output is correct
31 Correct 159 ms 436 KB Output is correct
32 Correct 136 ms 508 KB Output is correct