Submission #492207

#	Time	Username	Problem	Language	Result	Execution time	Memory
492207		ntarsis	Mobile (BOI12_mobile)	Pypy 3	25 / 100	1095 ms	131076 KiB

mobile

from math import sqrt
import sys
n,l = map(int,input().split())
nums = []
for i in range(n):
	a,b = sys.stdin.readline().split()
	a = int(a)
	b = int(b)
	nums.append([a,b])
lo = 0
ans = 80000000
hi = 80000000
def merge(intervals):
	ans = []
	for i in intervals:
		if not ans or ans[-1][1] < i[0]:
			ans.append(i)
			if len(ans)>1:
				return ans
		else:
			if ans[-1][1] < i[1]:
				ans[-1][1]=i[1]
	return ans
def check(x):
	intervals = []
	for i in nums:
		a,b = i[0],i[1]
		bruh = x*x-b*b
		if bruh>=0:
			c = sqrt(bruh)
			part1 = a-c
			part2 = a+c
			if bruh>=0 and part2>=0 and part1<l:
				intervals.append([part1,part2])
	intervals.sort()
	b = merge(intervals)
	return len(b)==1 and b[0][0]<=0 and b[0][1]>=l

while hi - lo > 10**-(3.3):
	mid = (hi+lo)/2
	if check(mid):
		ans = mid
		hi = mid
	else:
		lo = mid
print(ans)

• Subtask 1: 4 / 4
• Subtask 2: 4 / 4
• Subtask 3: 4 / 4
• Subtask 4: 4 / 4
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• Subtask 6: 5 / 5
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