def findMaximums(self, nums):
res = [0] * len(nums)
nums += [-1 * sys.maxint]
stack = [-1]
for i in xrange(len(nums)):
while nums[i] < (nums[stack[-1]] if stack[-1] >= 0 else -1 * sys.maxint):
res[i - stack[-2] - 2] = max(res[i - stack[-2] - 2], nums[stack[-1]])
stack.pop()
stack.append(i)
for i in reversed(xrange(len(nums) - 2)):
res[i] = max(res[i + 1], res[i])
return res
def findMaximums(self, nums: List[int]) -> List[int]:
ans = [0]*len(nums)
stack = []
for i, x in enumerate(nums + [0]):
while stack and stack[-1][1] >= x:
_, xx = stack.pop()
k = i-stack[-1][0]-2 if stack else i-1
ans[k] = max(ans[k], xx)
stack.append((i, x))
for i in reversed(range(len(nums)-1)):
ans[i] = max(ans[i], ans[i+1])
return ans
def findMaximums(self, nums: List[int]) -> List[int]:
N = len(nums)
cl = [None]*N
cr = [None]*N
stack = []
for i in range(N):
while stack and nums[stack[-1]]>=nums[i]:
stack.pop()
if not stack:
cl[i] = i+1
else:
cl[i] = i-stack[-1]
stack.append(i)
# now cl[i]==a means that nums[i] is a minimum of the range of length a starting from i
# and going to the left
stack = []
for i in range(N-1,-1,-1):
while stack and nums[stack[-1]]>=nums[i]:
stack.pop()
if not stack:
cr[i] = N-i
else:
cr[i] = stack[-1]-i
stack.append(i)
# now cr[i]==b means that nums[i] is a minimum of the range of length b starting from i
# and going to the right
cnt = [a+b-1 for a,b in zip(cl,cr)]
# cnt[i]==c means that there is a subarray of length c where nums[i] is a minimum
# and c is the maximum possible one
cnti = sorted(range(N), key=cnt.__getitem__, reverse=True) # reverse argsort
ofs = 0
ans = [None]*N
best = -10**10
for L in range(N,0,-1):
# will fill ans[L-1]
# ans[L-1] is the max of all such nums[i] that cnt[i]>=L
while ofs<N and cnt[cnti[ofs]]>=L:
best = max(best,nums[cnti[ofs]])
ofs += 1
ans[L-1] = best
return ans
def findMaximums(self, nums: List[int]) -> List[int]:
stack, n = [], len(nums)
ans = [0] * n
for i, num in enumerate(nums):
while stack and nums[stack[-1]] >= num: # ensure mono-increase
min_idx = stack.pop() # min_idx is the `stack_top_idx` we mentioned earlier, smallest between `left` and `right` below
left, right = (stack[-1] + 1) if stack else 0, i # left & right end of window, left is `second_stack_top_idx + 1`, right is `i`
window = right - left - 1 # window_size_idx = window size - 1
ans[window] = max(ans[window], nums[min_idx]) # update maximum
stack.append(i)
else:
while stack: # at the end of iteration, we want to pop out all elements in stack. Here assuming the `current_value` is super small, so that every number in the stack will be popped out
min_idx = stack.pop()
left, right = (stack[-1] + 1) if stack else 0, n
window = right - left - 1
ans[window] = max(ans[window], nums[min_idx])
for i in range(n-2, -1, -1): # update non-touched windows using result for larger windows
ans[i] = max(ans[i], ans[i+1])
return ans
def getExternalRPMS(self):
import stack.roll
import stack.gen
# The default-all distribution includes all of the
# installed pallets on the system and is used to generate a
# kickstart files for the everything appliance. This gives us
# a list of RPMs that we know we need from the source
# os/updates CDs.
cwd = os.getcwd()
print 'making default-all'
self.command('create.distribution', [ 'default-all',
'inplace=true', 'resolve=true', 'md5=false' ])
#
# copy the 'everything' node and graph file into the distribution
#
basedir = os.path.join('default-all', self.arch, 'build')
xml = self.command('list.node.xml', [ 'everything',
'basedir=%s' % basedir, 'eval=n' ] )
os.chdir(cwd)
#
# make sure the XML string is ASCII and not unicode,
# otherwise, the parser will fail
#
xmlinput = xml.encode('ascii', 'ignore')
generator = stack.gen.Generator_redhat()
generator.setArch(self.arch)
generator.setOS('redhat')
generator.parse(xmlinput)
rpms = []
for line in generator.generate('packages'):
if len(line) and line[0] not in [ '#', '%' ]:
rpms.append(line)
# The default-os distribution includes just the source
# os/update CDs (already in pallet form).
# The default-all distribution is
# still used for the comps file and the anaconda source
# code. We need this since anaconda and comps are missing
# from the foreign pallets (os/update CDs).
print 'making default-os'
self.command('create.distribution', [ 'default-os',
'inplace=true', 'resolve=true', 'md5=false' ])
#
# make sure a comps.xml file is present
#
comps = os.path.join('default-os', self.arch, 'RedHat',
'base', 'comps.xml')
if not os.path.exists(comps):
print '\n\tCould not find a comps.xml file.'
print '\tCopy a comps.xml file into the CentOS pallet\n'
sys.exit(-1)
#
# use yum to resolve dependencies
#
sys.path.append('/usr/lib/python2.6/site-packages')
sys.path.append('/usr/lib64/python2.6/site-packages')
sys.path.append('/usr/lib/python2.6/lib-dynload')
sys.path.append('/usr/lib64/python2.6/lib-dynload')
import yum
#
# need to create a repo here because the 'md5=false' flag above
# does not call createrepo and we need it below for yum to work
#
os.system('/usr/share/createrepo/genpkgmetadata.py ' +
'--groupfile RedHat/base/comps.xml ' +
'default-os/%s' % self.arch)
a = yum.YumBase()
a.doConfigSetup(fn='%s' % os.path.join(cwd, 'BUILD',
'roll-%s-%s' % (self.config.getRollName(),
self.config.getRollVersion()), 'yum.conf'),
init_plugins=False)
a.conf.cache = 0
a.doTsSetup()
a.doRepoSetup()
a.doRpmDBSetup()
a.doSackSetup()
a.doGroupSetup()
selected = []
for rpm in rpms + [ '@base', '@core' ]:
if rpm[0] == '@':
group = a.comps.return_group(
rpm[1:].encode('utf-8'))
for r in group.mandatory_packages.keys() + \
group.default_packages.keys():
if r not in selected:
selected.append(r)
elif rpm not in selected:
selected.append(rpm)
pkgs = []
avail = a.pkgSack.returnNewestByNameArch()
for p in avail:
if p.name in selected:
pkgs.append(p)
done = 0
while not done:
done = 1
results = a.findDeps(pkgs)
for pkg in results.keys():
for req in results[pkg].keys():
reqlist = results[pkg][req]
for r in reqlist:
if r.name not in selected:
selected.append(r.name)
pkgs.append(r)
done = 0
# Now build a list of rocks (required) and non-rocks (optional)
# rpms and return both of these list. When the ISOs are created
# all the required packages are first.
tree = stack.file.Tree(os.path.join(os.getcwd(),
'default-os', self.arch))
stack = []
nonstack = []
for rpm in tree.getFiles(os.path.join('RedHat', 'RPMS')):
if rpm.getBaseName() in selected:
stack.append(rpm)
else:
nonstack.append(rpm)
return (stack, nonstack)
queue.pop()
queue.append(i)
if i - last + 1 == length:
max_min = max(max_min, nums[queue[0]])
return max_min
return [helper(i + 1) for i in range(len(nums))]
It turned out that this is a tricky problem using monotonic stack, where the poped up value might be the result for the query with length of stack[-1] ... current i. Why?
We maintain the increasing monotonic stack, keeping popup the stack[-1] if nums[stack[-1]] >= num, and we havenums[stack[-2]] < nums[stack[-1]] >= num. So the nums[stack[-1]] is the minimum value of subarray with range of [stack[-2] +1: i - 1]. Because if there is any larger value x in the range, the stack[-1] should have been popped up when seeing x. So we can update the query[range] with nums[stack[-1]].
Finally, there is possible to be no result yet for some queris. With observation, the maximum value would be the result of query[0], and the minimum value would be the result of query[-1], so the query array is actually deceasing. Then we can fill up the empty slot in query array by propagating the previous value.
def findMaximums(self, nums: List[int]) -> List[int]:
stack = []
nums = [-1] + nums + [0]
n = len(nums)
res = [0] * (n - 2)
for i, num in enumerate(nums):
while stack and nums[stack[-1]] >= num:
j = stack.pop()
k = i - 1 - (stack[-1] + 1)
res[k] = max(res[k], nums[j])
stack.append(i)
for i in range(n - 3, 0, -1):
res[i - 1] = max(res[i], res[i - 1])
return res
def dec_binary(num):
if num > 1:
dec_binary(num//2)
stack.append(str(num % 2))
def getExternalRPMS(self):
import stack.roll
import stack.gen
# The default-all distribution includes all of the
# installed pallets on the system and is used to generate a
# kickstart files for the everything appliance. This gives us
# a list of RPMs that we know we need from the source
# os/updates CDs.
cwd = os.getcwd()
print 'making default-all'
self.command(
'create.distribution',
['default-all', 'inplace=true', 'resolve=true', 'md5=false'])
#
# copy the 'everything' node and graph file into the distribution
#
basedir = os.path.join('default-all', self.arch, 'build')
xml = self.command(
'list.node.xml',
['everything', 'basedir=%s' % basedir, 'eval=n'])
os.chdir(cwd)
#
# make sure the XML string is ASCII and not unicode,
# otherwise, the parser will fail
#
xmlinput = xml.encode('ascii', 'ignore')
generator = stack.gen.Generator_redhat()
generator.setArch(self.arch)
generator.setOS('redhat')
generator.parse(xmlinput)
rpms = []
for line in generator.generate('packages'):
if len(line) and line[0] not in ['#', '%']:
rpms.append(line)
# The default-os distribution includes just the source
# os/update CDs (already in pallet form).
# The default-all distribution is
# still used for the comps file and the anaconda source
# code. We need this since anaconda and comps are missing
# from the foreign pallets (os/update CDs).
print 'making default-os'
self.command(
'create.distribution',
['default-os', 'inplace=true', 'resolve=true', 'md5=false'])
#
# make sure a comps.xml file is present
#
comps = os.path.join('default-os', self.arch, 'RedHat', 'base',
'comps.xml')
if not os.path.exists(comps):
print '\n\tCould not find a comps.xml file.'
print '\tCopy a comps.xml file into the CentOS pallet\n'
sys.exit(-1)
#
# use yum to resolve dependencies
#
if stack.release == '7.x':
pythonver = '2.7'
else:
pythonver = '2.6'
sys.path.append('/usr/lib/python%s/site-packages' % pythonver)
sys.path.append('/usr/lib64/python%s/site-packages' % pythonver)
sys.path.append('/usr/lib/python%s/lib-dynload' % pythonver)
sys.path.append('/usr/lib64/python%s/lib-dynload' % pythonver)
import yum
#
# need to create a repo here because the 'md5=false' flag above
# does not call createrepo and we need it below for yum to work
#
os.system('/usr/share/createrepo/genpkgmetadata.py ' +
'--groupfile RedHat/base/comps.xml ' +
'default-os/%s' % self.arch)
a = yum.YumBase()
a.doConfigSetup(fn='%s' % os.path.join(
cwd, 'BUILD', 'roll-%s-%s' %
(self.config.getRollName(), self.config.getRollVersion()),
'yum.conf'),
init_plugins=False)
a.conf.cache = 0
a.doTsSetup()
a.doRepoSetup()
a.doRpmDBSetup()
a.doSackSetup()
a.doGroupSetup()
selected = []
for rpm in rpms + ['@base', '@core']:
if rpm[0] == '@':
group = a.comps.return_group(rpm[1:].encode('utf-8'))
for r in group.mandatory_packages.keys() + \
group.default_packages.keys():
if r not in selected:
selected.append(r)
elif rpm not in selected:
selected.append(rpm)
pkgs = []
avail = a.pkgSack.returnNewestByNameArch()
for p in avail:
if p.name in selected:
pkgs.append(p)
done = 0
while not done:
done = 1
results = a.findDeps(pkgs)
for pkg in results.keys():
for req in results[pkg].keys():
reqlist = results[pkg][req]
for r in reqlist:
if r.name not in selected:
selected.append(r.name)
pkgs.append(r)
done = 0
# Now build a list of rocks (required) and non-rocks (optional)
# rpms and return both of these list. When the ISOs are created
# all the required packages are first.
tree = stack.file.Tree(
os.path.join(os.getcwd(), 'default-os', self.arch))
stack = []
nonstack = []
for rpm in tree.getFiles(os.path.join('RedHat', 'RPMS')):
if rpm.getBaseName() in selected:
stack.append(rpm)
else:
nonstack.append(rpm)
return (stack, nonstack)