oj.uz

Submission #486976

# Submission time Handle Problem Language Result Execution time Memory
486976 2021-11-13T16:41:56 Z Duy_e Global Warming (CEOI18_glo) C++14
100 / 100
 56 ms 8452 KB 
#include <bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define pii pair<long long, long long>
#define st first
#define nd second
#define file "test"
using namespace std;
const long long oo = 1e18;
const long long N = 2e5 + 5;

ll n, a[N], x, lis[N], lds[N];
vector <ll> dp(N, 3e9);

int main()
{
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	//#ifndef ONLINE_JUDGE
	//	freopen(file".inp","r",stdin); freopen(file".out","w",stdout);
	//#endif
	
	cin >> n >> x;
	for (int i = 1; i <= n; i ++)
		cin >> a[i];

	for (int i = n; i >= 1; i --){
		lds[i] = lower_bound(dp.begin(), dp.end(), - a[i]) - dp.begin() + 1;
		dp[lds[i] - 1] = -a[i];
	}

	dp.assign(N, 3e9);
	ll ans = 0;
	for (int i = 1; i <= n; i ++){
		lis[i] = lower_bound(dp.begin(), dp.end(), a[i] - x) - dp.begin() + 1;
		

		ans = max(ans, lower_bound(dp.begin(), dp.end(), a[i]) - dp.begin() + lds[i]);

		dp[lis[i] - 1] = a[i] - x;
		// cout << lis[i] << ' ';
	}

	cout << ans;

	return 0;
}	
/**  /\_/\
    (= ._.)
    / >0  \>1 
  ________________________
 / Brainstorming section /
/=======================/
---
===
To be frank I did not quite get your way of thinking, but let me put it my way. 
Let's say we modify some subsegment [i, j] (we do not say anything about whether 
some points in it will belong to our final LIS or whatever). 
Let's say we move it down by y. 
We can note that we in fact can move down [1, i-1] segment as well, 
because moving down some prefix never decreases LIS. 
So it turns out that we can in fact restrict to moving prefix [1, j] down under the assumption
that we moved our subsegment down. Moreover we can move it down as far as we can and 
it will not worsen our answer, so we can restrict our move here to x what almost proves my claim.
There is second case to consider of subsegment being moved up, 
in which case we see that we can move suffix [i, n] by x up, but that is 
the same as moving prefix [1, i-1] down by x.
===
**/
// Before submit: spot the visible bug by reading the code.

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1868 KB Output is correct
2 Correct 1 ms 1868 KB Output is correct
3 Correct 1 ms 1868 KB Output is correct
4 Correct 1 ms 1868 KB Output is correct
5 Correct 1 ms 1868 KB Output is correct
6 Correct 1 ms 1868 KB Output is correct
7 Correct 1 ms 1868 KB Output is correct
8 Correct 2 ms 1868 KB Output is correct
9 Correct 1 ms 1900 KB Output is correct
10 Correct 1 ms 1900 KB Output is correct
11 Correct 1 ms 1896 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1868 KB Output is correct
2 Correct 1 ms 1868 KB Output is correct
3 Correct 1 ms 1868 KB Output is correct
4 Correct 1 ms 1868 KB Output is correct
5 Correct 1 ms 1868 KB Output is correct
6 Correct 1 ms 1868 KB Output is correct
7 Correct 1 ms 1868 KB Output is correct
8 Correct 2 ms 1868 KB Output is correct
9 Correct 1 ms 1900 KB Output is correct
10 Correct 1 ms 1900 KB Output is correct
11 Correct 1 ms 1896 KB Output is correct
12 Correct 1 ms 1868 KB Output is correct
13 Correct 1 ms 1868 KB Output is correct
14 Correct 1 ms 1868 KB Output is correct
15 Correct 1 ms 1868 KB Output is correct
16 Correct 1 ms 1868 KB Output is correct
17 Correct 2 ms 1900 KB Output is correct
18 Correct 1 ms 1892 KB Output is correct

Subtask #3
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1868 KB Output is correct
2 Correct 1 ms 1868 KB Output is correct
3 Correct 1 ms 1868 KB Output is correct
4 Correct 1 ms 1868 KB Output is correct
5 Correct 1 ms 1868 KB Output is correct
6 Correct 1 ms 1868 KB Output is correct
7 Correct 1 ms 1868 KB Output is correct
8 Correct 2 ms 1868 KB Output is correct
9 Correct 1 ms 1900 KB Output is correct
10 Correct 1 ms 1900 KB Output is correct
11 Correct 1 ms 1896 KB Output is correct
12 Correct 1 ms 1868 KB Output is correct
13 Correct 1 ms 1868 KB Output is correct
14 Correct 1 ms 1868 KB Output is correct
15 Correct 1 ms 1868 KB Output is correct
16 Correct 1 ms 1868 KB Output is correct
17 Correct 2 ms 1900 KB Output is correct
18 Correct 1 ms 1892 KB Output is correct
19 Correct 1 ms 1868 KB Output is correct
20 Correct 2 ms 1868 KB Output is correct
21 Correct 1 ms 1868 KB Output is correct
22 Correct 2 ms 1868 KB Output is correct
23 Correct 2 ms 1868 KB Output is correct
24 Correct 2 ms 1868 KB Output is correct
25 Correct 2 ms 1896 KB Output is correct
26 Correct 1 ms 1868 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 56 ms 8388 KB Output is correct
2 Correct 55 ms 8400 KB Output is correct
3 Correct 55 ms 8444 KB Output is correct
4 Correct 52 ms 8448 KB Output is correct
5 Correct 38 ms 7724 KB Output is correct

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 14 ms 3532 KB Output is correct
2 Correct 13 ms 3532 KB Output is correct
3 Correct 17 ms 3464 KB Output is correct
4 Correct 12 ms 3276 KB Output is correct
5 Correct 2 ms 1972 KB Output is correct
6 Correct 11 ms 3268 KB Output is correct
7 Correct 13 ms 3552 KB Output is correct

Subtask #6
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 23 ms 5136 KB Output is correct
2 Correct 24 ms 5184 KB Output is correct
3 Correct 47 ms 8384 KB Output is correct
4 Correct 41 ms 7704 KB Output is correct
5 Correct 19 ms 4812 KB Output is correct
6 Correct 31 ms 7468 KB Output is correct
7 Correct 36 ms 8188 KB Output is correct
8 Correct 22 ms 5100 KB Output is correct

Subtask #7
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1868 KB Output is correct
2 Correct 1 ms 1868 KB Output is correct
3 Correct 1 ms 1868 KB Output is correct
4 Correct 1 ms 1868 KB Output is correct
5 Correct 1 ms 1868 KB Output is correct
6 Correct 1 ms 1868 KB Output is correct
7 Correct 1 ms 1868 KB Output is correct
8 Correct 2 ms 1868 KB Output is correct
9 Correct 1 ms 1900 KB Output is correct
10 Correct 1 ms 1900 KB Output is correct
11 Correct 1 ms 1896 KB Output is correct
12 Correct 1 ms 1868 KB Output is correct
13 Correct 1 ms 1868 KB Output is correct
14 Correct 1 ms 1868 KB Output is correct
15 Correct 1 ms 1868 KB Output is correct
16 Correct 1 ms 1868 KB Output is correct
17 Correct 2 ms 1900 KB Output is correct
18 Correct 1 ms 1892 KB Output is correct
19 Correct 1 ms 1868 KB Output is correct
20 Correct 2 ms 1868 KB Output is correct
21 Correct 1 ms 1868 KB Output is correct
22 Correct 2 ms 1868 KB Output is correct
23 Correct 2 ms 1868 KB Output is correct
24 Correct 2 ms 1868 KB Output is correct
25 Correct 2 ms 1896 KB Output is correct
26 Correct 1 ms 1868 KB Output is correct
27 Correct 56 ms 8388 KB Output is correct
28 Correct 55 ms 8400 KB Output is correct
29 Correct 55 ms 8444 KB Output is correct
30 Correct 52 ms 8448 KB Output is correct
31 Correct 38 ms 7724 KB Output is correct
32 Correct 14 ms 3532 KB Output is correct
33 Correct 13 ms 3532 KB Output is correct
34 Correct 17 ms 3464 KB Output is correct
35 Correct 12 ms 3276 KB Output is correct
36 Correct 2 ms 1972 KB Output is correct
37 Correct 11 ms 3268 KB Output is correct
38 Correct 13 ms 3552 KB Output is correct
39 Correct 23 ms 5136 KB Output is correct
40 Correct 24 ms 5184 KB Output is correct
41 Correct 47 ms 8384 KB Output is correct
42 Correct 41 ms 7704 KB Output is correct
43 Correct 19 ms 4812 KB Output is correct
44 Correct 31 ms 7468 KB Output is correct
45 Correct 36 ms 8188 KB Output is correct
46 Correct 22 ms 5100 KB Output is correct
47 Correct 25 ms 5192 KB Output is correct
48 Correct 28 ms 5100 KB Output is correct
49 Correct 53 ms 8372 KB Output is correct
50 Correct 39 ms 7700 KB Output is correct
51 Correct 30 ms 6152 KB Output is correct
52 Correct 36 ms 7728 KB Output is correct
53 Correct 33 ms 7708 KB Output is correct
54 Correct 38 ms 8452 KB Output is correct
55 Correct 42 ms 8404 KB Output is correct