Created
September 26, 2020 23:03
-
-
Save monhime/b942251fa41a20d3428e959853290b92 to your computer and use it in GitHub Desktop.
ALCDC D問題 解答
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
import sys | |
def input(): return sys.stdin.readline().rstrip() | |
from fractions import gcd | |
class seg(): | |
def __init__(self,init_val): | |
self.n=len(init_val) | |
self.ide_ele= 0 #単位元 | |
self.num=2**(self.n-1).bit_length() #n以上の最小の2のべき乗 | |
self.seg=[self.ide_ele]*2*self.num | |
for i in range(self.n): | |
self.seg[i+self.num-1]=init_val[i] | |
for i in range(self.num-2,-1,-1): | |
self.seg[i]=self.seg_func(self.seg[2*i+1],self.seg[2*i+2]) | |
def seg_func(self,a,b): | |
#return a+b #0 | |
#return a*b #1 | |
#return gcd(a,b) #0 | |
return max(a,b) #0か-1か-10**10 (十分小さいもの,計算に使う場合0) | |
#return min(a,b) #10**10 (十分大きいもの) | |
def update(self,k,x): | |
k+=self.num-1 | |
self.seg[k]=x | |
while k: | |
k=(k-1)//2 | |
self.seg[k]=self.seg_func(self.seg[k*2+1],self.seg[k*2+2]) | |
def query(self,p,q): #O(logN) | |
if q<=p:return self.ide_ele | |
p+=self.num-1 | |
q+=self.num-2 | |
self.res=self.ide_ele | |
while q-p>1: | |
if p&1==0: | |
self.res=self.seg_func(self.res,self.seg[p]) | |
if q&1==1: | |
self.res=self.seg_func(self.res,self.seg[q]) | |
q-=1 | |
p=p//2 | |
q=(q-1)//2 | |
if p==q:self.res=self.seg_func(self.res,self.seg[p]) | |
else:self.res=self.seg_func(self.seg_func(self.res,self.seg[p]),self.seg[q]) | |
return self.res | |
def main(): | |
n, k = map(int,input().split()) | |
A = [int(input())for _ in range(n)] | |
max_a = max(A) | |
A_len = [0] * (max_a + 1) # 最後の数字がiのときの最大長さ | |
SEG = seg(A_len) | |
for a in A: | |
SEG.update(a, SEG.query(max(a - k, 0), min(a + k, max_a) + 1) + 1) | |
print(SEG.query(0, max_a + 1)) | |
if __name__=='__main__': | |
main() |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment