Submission #367223

#	Time	Username	Problem	Language	Result	Execution time	Memory
367223		leu_naut	Global Warming (CEOI18_glo)	C++11	100 / 100	64 ms	4332 KiB

glo

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
 
#define FOR(i,a,b) for (int i = a; i <= b; ++i)
#define FORd(i,a,b) for (int i = a; i >= b; --i)
#define FastRead ios_base::sync_with_stdio(0); cin.tie(nullptr);
#define II pair <ll,ll>
 
const int N = 2e5;
const ll oo = 1e18;
const int maxN = 2e9;
const int MOD = 1e9 + 7;
 
ll a[N + 10], dp[N + 10];
 
int main()	
{	
/*#ifndef ONLINE_JUDGE
	freopen("input.txt","r",stdin);
	freopen("output.txt","w",stdout);
#endif //ONLINE_JUDGE */
	FastRead	
	int n,x;
	ll k = 0;
	cin >> n >> x;
	for (int i = 0; i < n; ++i) cin >> a[i];
	vector <ll> lis;
	//Longest increasing subsequence ending at pos i
	for (int i = 0; i < n; ++i)	{
		int pos = lower_bound(lis.begin(),lis.end(),a[i]) - lis.begin();
		if (pos == lis.size()) lis.push_back(a[i]);
		else lis[pos] = a[i];
		dp[i] = pos + 1;
		k = max(k, dp[i]);
	}
	lis.clear();
	//Longest increasing subsequence starting at pos i and decrease all [1,i] by x
	//= Longest increase minus subsequence ending at pos i with reverse array and plus x.
	for (int i = n - 1; i >= 0; --i) {
		ll p = lower_bound(lis.begin(),lis.end(), -a[i] + x) - lis.begin();
		int pos = lower_bound(lis.begin(),lis.end(),-a[i]) - lis.begin();
		if (pos == lis.size()) lis.push_back(-a[i]);
		else lis[pos] = -a[i];
		k = max(k,dp[i] + p);
	}
	cout << k;
}	

Compilation message (stderr)

glo.cpp: In function 'int main()':
glo.cpp:34:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   34 |   if (pos == lis.size()) lis.push_back(a[i]);
      |       ~~~~^~~~~~~~~~~~~
glo.cpp:45:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   45 |   if (pos == lis.size()) lis.push_back(-a[i]);
      |       ~~~~^~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 13 / 13
• Subtask 4: 10 / 10
• Subtask 5: 20 / 20
• Subtask 6: 17 / 17
• Subtask 7: 25 / 25