Submission #468841

# Submission time Handle Problem Language Result Execution time Memory
468841 2021-08-29T19:51:47 Z mychecksedad Exam (eJOI20_exam) C++17
77 / 100
234 ms 98856 KB
#include <bits/stdc++.h>
using namespace std;
const int N = 1e5+10, K = 20;
#define pb push_back
#define all(v) v.begin(), v.end()
int n, a[N], b[N], rmq[N][K];
map<int, vector<int>> m;

int subtask2(){
	int ans = 0;
	vector<bool> is_taken(n + 5, 0);
	for(int i = 1; i <= n; i++){
		if(a[i] == b[1]){
			ans++;
			int l = i-1, r = i + 1;
			is_taken[i] = 1;
			for(; l >= 1 && !is_taken[l] && a[l] < b[1]; l--) ans++, is_taken[l] = 1;
			for(; r <= n && !is_taken[r] && a[r] < b[1]; r++) ans++, is_taken[r] = 1;
		}
	}
	return ans;
}
int Q(int l, int r){
	int k = __lg((r-l+1));
	return max(rmq[l][k], rmq[r - (1<<k) + 1][k]);
}
int subtask4(){
	map<int, int> m;
	for(int i = 1; i <= n; i++) m[a[i]] = i;
	vector<int> dp(n+2), v(1), lis(1);
	for(int i = 1; i <= n; i++){
		if(a[i] <= b[i]){
			int pos = m[b[i]];
			if(pos > 0 && Q(min(i, pos), max(i, pos)) <= b[i]){
				v.pb(pos);
			}
		}
	}	
	int ans = 0;
	for(int i = 1; i < v.size(); i++){
		int l = lower_bound(all(lis), v[i]) - lis.begin();
		if(l == lis.size()) lis.pb(l);
		else{
			lis[l] = v[i];
		}
	}
	return int(lis.size())-1;
}
void precalc(){
	for(int i = 1; i <= n; i++) rmq[i][0] = a[i];
	for(int j = 1; j < K; j++){
		for(int i = 1; i + (1<<j) <= n + 1; i++){
			rmq[i][j] = max(rmq[i][j - 1], rmq[i + (1<<(j-1))][j - 1]);
		}
	}
}

int main(){
	cin.tie(0); ios::sync_with_stdio(0);
	cin >> n;
	for(int i = 1; i <= n; i++) cin >> a[i];
	for(int i = 1; i <= n; i++) cin >> b[i];
	precalc();
	bool is_b = 1;
	for(int i = 2; i <= n; i++) if(b[i] != b[i - 1]) is_b = 0;
	if(is_b){
		cout << subtask2();
		return 0;
	}
	if(n > 5000){
		cout << subtask4();
		return 0;
	}
	int ans = 0;
	vector<vector<int>> dp(n+2, vector<int>(n+2));
	for(int i = 1; i <= n; i++){
		int mx = 0;
		for(int j = 1; j <= n; j++){
			int x = Q(min(i, j), max(i, j));
			mx = max(mx, dp[i - 1][j]);
			if(x > b[i]){
				dp[i][j] = mx;
			}else{
				if(a[i] <= b[i] && a[j] == b[i]){
					dp[i][j] = mx + 1;
				}else dp[i][j] = mx;
			}
			if(i==n) ans=max(ans, dp[i][j]);
		}
	}


	cout << ans;


	return 0;
}

Compilation message

exam.cpp: In function 'int subtask4()':
exam.cpp:40:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   40 |  for(int i = 1; i < v.size(); i++){
      |                 ~~^~~~~~~~~~
exam.cpp:42:8: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |   if(l == lis.size()) lis.pb(l);
      |      ~~^~~~~~~~~~~~~
exam.cpp:39:6: warning: unused variable 'ans' [-Wunused-variable]
   39 |  int ans = 0;
      |      ^~~
# Verdict Execution time Memory Grader output
1 Correct 0 ms 332 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 0 ms 332 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 0 ms 332 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 332 KB Output is correct
2 Correct 6 ms 1996 KB Output is correct
3 Correct 24 ms 8040 KB Output is correct
4 Correct 24 ms 8908 KB Output is correct
5 Correct 38 ms 8852 KB Output is correct
6 Correct 24 ms 8876 KB Output is correct
7 Correct 31 ms 8824 KB Output is correct
8 Correct 37 ms 8880 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 3 ms 1384 KB Output is correct
3 Correct 34 ms 16268 KB Output is correct
4 Correct 198 ms 91156 KB Output is correct
5 Correct 209 ms 98852 KB Output is correct
6 Correct 234 ms 98856 KB Output is correct
# Verdict Execution time Memory Grader output
1 Incorrect 3 ms 972 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 0 ms 332 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 0 ms 332 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 0 ms 332 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 332 KB Output is correct
9 Correct 1 ms 332 KB Output is correct
10 Correct 1 ms 460 KB Output is correct
11 Correct 1 ms 460 KB Output is correct
12 Correct 1 ms 460 KB Output is correct
13 Correct 1 ms 460 KB Output is correct
14 Correct 1 ms 460 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 0 ms 332 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 0 ms 332 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 0 ms 332 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 0 ms 204 KB Output is correct
8 Correct 3 ms 1384 KB Output is correct
9 Correct 34 ms 16268 KB Output is correct
10 Correct 198 ms 91156 KB Output is correct
11 Correct 209 ms 98852 KB Output is correct
12 Correct 234 ms 98856 KB Output is correct
13 Correct 1 ms 204 KB Output is correct
14 Correct 0 ms 332 KB Output is correct
15 Correct 1 ms 332 KB Output is correct
16 Correct 1 ms 460 KB Output is correct
17 Correct 1 ms 460 KB Output is correct
18 Correct 1 ms 460 KB Output is correct
19 Correct 1 ms 460 KB Output is correct
20 Correct 1 ms 460 KB Output is correct
21 Correct 1 ms 460 KB Output is correct
22 Correct 10 ms 4400 KB Output is correct
23 Correct 2 ms 716 KB Output is correct
24 Correct 232 ms 98852 KB Output is correct
25 Correct 204 ms 98848 KB Output is correct
26 Correct 206 ms 98780 KB Output is correct
27 Correct 208 ms 98764 KB Output is correct
28 Correct 203 ms 98848 KB Output is correct
29 Correct 208 ms 98756 KB Output is correct
30 Correct 212 ms 98788 KB Output is correct
31 Correct 208 ms 98756 KB Output is correct
32 Correct 204 ms 98776 KB Output is correct