Submission #259914

#	Time	Username	Problem	Language	Result	Execution time	Memory
259914		Kenzo_1114	Global Warming (CEOI18_glo)	C++17	17 / 100	74 ms	6520 KiB

glo

#include<bits/stdc++.h>
using namespace std;
const int MAXN = 200010;
const long long int INF = 2e10 + 9;
const long long int MAX = 1e9;
 
int n;
long long int x, t[MAXN], dp[MAXN], l[MAXN], ans[MAXN];
 
int main ()
{
	scanf("%d %lld", &n, &x);
 
	dp[0] = INF;
	for(int i = 1; i <= n; i++)	
		scanf("%lld", &t[i]), dp[i] = INF;
 
	t[0] = -INF;
	for(int i = 1; i <= n; i++)
	{
		int cur = i - 1;
		while(t[cur] - x >= t[i])	cur = l[cur];
		l[i] = cur;
	}
	
	for(int i = 1, mx = 0; i <= n; i++)
	{
		int it = lower_bound(dp, dp + n, t[i]) - dp;
		dp[it] = t[i];
		mx = max(mx, it + 1);
		ans[i] = mx;
	}
 
	dp[0] = INF;
	for(int i = 1; i <= n; i++)	t[i] = MAX - t[i], dp[i] = INF;
 
	long long int ANS = 0;
	for(int i = n; i > 0; i--)
	{
		int it = lower_bound(dp, dp + n, t[i]) - dp;
		dp[it] = t[i];
		ANS = max(ANS, it + 1 + ans[l[i]]);
	}	
 
	printf("%lld\n", ANS);
}

Compilation message (stderr)

glo.cpp: In function 'int main()':
glo.cpp:12:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %lld", &n, &x);
  ~~~~~^~~~~~~~~~~~~~~~~~~
glo.cpp:16:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%lld", &t[i]), dp[i] = INF;
   ~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 10
• Subtask 3: 0 / 13
• Subtask 4: 0 / 10
• Subtask 5: 0 / 20
• Subtask 6: 17 / 17
• Subtask 7: 0 / 25