Submission #73925

#	Time	Username	Problem	Language	Result	Execution time	Memory
73925		haitun	Global Warming (CEOI18_glo)	C++14	100 / 100	210 ms	4604 KiB

glo

#include <bits/stdc++.h>
//#include "functions.h"
#define FOR(x,y) for(int x = 0; x < y; x++)
#define ALLR(x) x.begin(),x.end()
#define con continue
#define ll long long
#define LINF LLONG_MAX
#define INF INT_MAX
#define pii pair<int,int>
#define vi vector <int>
#define pb push_back
#define F first
#define S second
#define len(x) x.length()
#define sz(x) x.size()
#define SEE(v)	for(auto x : v)	cout << x << " "; cout << endl;
using namespace std;

int n, b;

int CeilIndex(vi v, int l, int r, int key){

	while(r - l > 1)
	{
		int m = l + (r - l) / 2;
		if (v[m] >= key)	r = m;
		else				l = m;
	}

	return r;
}

int RCeilIndex(vi v, int l, int r, int key) {

	while(r - l > 1)
	{
		int m = l + (r - l) / 2;
		if(v[m] <= key)	r = m;
		else			l = m;
	}

	return r;
}

int LongestIncreasingSubsequenceLength(vi v,vi &front) {

	if(v.size() == 0)	return 0;

	vi tail(v.size(), INF);
	int length = 1;

	front[0] = 0;
	tail[0] = v[0];

	for(int i = 1; i < v.size(); i++)
	{
		int pos = upper_bound(ALLR(tail), v[i] + b - 1) - tail.begin();
		front[i] = pos;

		if(v[i] < tail[0])					tail[0] = v[i];
		else if(v[i] > tail[length - 1])	tail[length++] = v[i];
		else								tail[lower_bound(tail.begin(), tail.begin() + length - 1, v[i]) - tail.begin()] = v[i];
	}

	return length;
}

int LongestDecreasingSubsequenceLength(vi v, vi &back) {

	if (v.size() == 0)	return 0;

	vi tail(v.size(), -1);
	int length = 1;

	back[0] = 1;
	tail[0] = v[0];

	for(int i = 1; i < v.size(); i++)
	{
		//int pos = RCeilIndex(tail, -1, length - 1, v[i]);
		int pos = lower_bound(tail.begin(), tail.begin() + length - 1, v[i], greater <int> ()) - tail.begin();

		if(v[i] > tail[0])					tail[0] = v[i], back[i] = 1;
		else if (v[i] < tail[length - 1])	tail[length++] = v[i], back[i] = length;
		else								tail[pos] = v[i], back[i] = pos + 1;

		//if you are not the head, length = 0;

		//back[i] = length;
	}

	return length;
}

int main() {

	//freopen("test.txt", "r",stdin);
	//int n, b;
	cin >> n >> b;

	vi t(n), front(n), back(n);
	FOR(j, n)   cin >> t[j];
	
	int ans = LongestIncreasingSubsequenceLength(t, front);

	if(b == 0)
	{
		cout << LongestIncreasingSubsequenceLength(t, front);
		return 0;
	}

	reverse(ALLR(t));
	LongestDecreasingSubsequenceLength(t, back);
	reverse(ALLR(back));
	//SEE(front);
	//SEE(back);
	for(int j = n - 1; j >= 0; j--)	ans = max(ans, front[j] + back[j]);
	cout << ans;
}

Compilation message (stderr)

glo.cpp: In function 'int LongestIncreasingSubsequenceLength(std::vector<int>, std::vector<int>&)':
glo.cpp:55:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 1; i < v.size(); i++)
                 ~~^~~~~~~~~~
glo.cpp: In function 'int LongestDecreasingSubsequenceLength(std::vector<int>, std::vector<int>&)':
glo.cpp:78:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 1; i < v.size(); 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