Submission #518723

#	Time	Username	Problem	Language	Result	Execution time	Memory
518723		zhangjishen	Global Warming (CEOI18_glo)	C++98	100 / 100	65 ms	3412 KiB

glo

#include<bits/stdc++.h>
using namespace std;

#define mp make_pair
#define pb push_back
#define fi first
#define se second
template<typename T> bool chkmin(T &a, T b){return b < a ? a = b, 1 : 0;}
template<typename T> bool chkmax(T &a, T b){return b > a ? a = b, 1 : 0;}
const int inf = 2e9 + 10, MAXN = 2e5 + 10;

int n, x, a[MAXN], f[MAXN], L[MAXN], R[MAXN];
int main(){
	// input
	scanf("%d %d", &n, &x);
	for(int i = 1; i <= n; i++)
		scanf("%d", &a[i]);
	// L
	for(int i = 1; i <= n; i++)
		f[i] = inf;
	for(int i = 1; i <= n; i++){
		L[i] = lower_bound(f + 1, f + 1 + n, a[i] + x) - f;
		int j = lower_bound(f + 1, f + 1 + n, a[i]) - f;
		f[j] = a[i];
	}
	// R
	for(int i = 1; i <= n; i++)
		f[i] = inf;
	for(int i = n; i >= 1; i--){	// LDS of reverse = LIS of - reverse
		R[i] = lower_bound(f + 1, f + 1 + n, -a[i]) - f;
		f[R[i]] = -a[i];
	}
	// ans
	int ans = 0;
	for(int i = 1; i <= n; i++)
		chkmax(ans, L[i] + R[i] - 1);
	printf("%d\n", ans);
}

Compilation message (stderr)

glo.cpp: In function 'int main()':
glo.cpp:15:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |  scanf("%d %d", &n, &x);
      |  ~~~~~^~~~~~~~~~~~~~~~~
glo.cpp:17:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 |   scanf("%d", &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