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psf/black code formatting (#1277)

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This commit is contained in:
William Zhang
2019-10-05 01:14:13 -04:00
committed by Christian Clauss
parent 07f04a2e55
commit 9eac17a408
291 changed files with 6014 additions and 4571 deletions
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76
data_structures/binary_tree/lazy_segment_tree.py
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@ -1,34 +1,38 @@
import math
class SegmentTree:
class SegmentTree:
def __init__(self, N):
self.N = N
self.st = [0 for i in range(0,4*N)] # approximate the overall size of segment tree with array N
self.lazy = [0 for i in range(0,4*N)] # create array to store lazy update
self.flag = [0 for i in range(0,4*N)] # flag for lazy update
self.st = [
0 for i in range(0, 4 * N)
] # approximate the overall size of segment tree with array N
self.lazy = [0 for i in range(0, 4 * N)] # create array to store lazy update
self.flag = [0 for i in range(0, 4 * N)] # flag for lazy update
def left(self, idx):
return idx*2
return idx * 2
def right(self, idx):
return idx*2 + 1
return idx * 2 + 1
def build(self, idx, l, r, A):
if l==r:
self.st[idx] = A[l-1]
else :
mid = (l+r)//2
self.build(self.left(idx),l,mid, A)
self.build(self.right(idx),mid+1,r, A)
self.st[idx] = max(self.st[self.left(idx)] , self.st[self.right(idx)])
if l == r:
self.st[idx] = A[l - 1]
else:
mid = (l + r) // 2
self.build(self.left(idx), l, mid, A)
self.build(self.right(idx), mid + 1, r, A)
self.st[idx] = max(self.st[self.left(idx)], self.st[self.right(idx)])
# update with O(lg N) (Normal segment tree without lazy update will take O(Nlg N) for each update)
def update(self, idx, l, r, a, b, val): # update(1, 1, N, a, b, v) for update val v to [a,b]
def update(
self, idx, l, r, a, b, val
): # update(1, 1, N, a, b, v) for update val v to [a,b]
if self.flag[idx] == True:
self.st[idx] = self.lazy[idx]
self.flag[idx] = False
if l!=r:
if l != r:
self.lazy[self.left(idx)] = self.lazy[idx]
self.lazy[self.right(idx)] = self.lazy[idx]
self.flag[self.left(idx)] = True
@ -36,22 +40,22 @@ class SegmentTree:
if r < a or l > b:
return True
if l >= a and r <= b :
if l >= a and r <= b:
self.st[idx] = val
if l!=r:
if l != r:
self.lazy[self.left(idx)] = val
self.lazy[self.right(idx)] = val
self.flag[self.left(idx)] = True
self.flag[self.right(idx)] = True
return True
mid = (l+r)//2
self.update(self.left(idx),l,mid,a,b,val)
self.update(self.right(idx),mid+1,r,a,b,val)
self.st[idx] = max(self.st[self.left(idx)] , self.st[self.right(idx)])
mid = (l + r) // 2
self.update(self.left(idx), l, mid, a, b, val)
self.update(self.right(idx), mid + 1, r, a, b, val)
self.st[idx] = max(self.st[self.left(idx)], self.st[self.right(idx)])
return True
# query with O(lg N)
def query(self, idx, l, r, a, b): #query(1, 1, N, a, b) for query max of [a,b]
def query(self, idx, l, r, a, b): # query(1, 1, N, a, b) for query max of [a,b]
if self.flag[idx] == True:
self.st[idx] = self.lazy[idx]
self.flag[idx] = False
@ -64,27 +68,27 @@ class SegmentTree:
return -math.inf
if l >= a and r <= b:
return self.st[idx]
mid = (l+r)//2
q1 = self.query(self.left(idx),l,mid,a,b)
q2 = self.query(self.right(idx),mid+1,r,a,b)
return max(q1,q2)
mid = (l + r) // 2
q1 = self.query(self.left(idx), l, mid, a, b)
q2 = self.query(self.right(idx), mid + 1, r, a, b)
return max(q1, q2)
def showData(self):
showList = []
for i in range(1,N+1):
for i in range(1, N + 1):
showList += [self.query(1, 1, self.N, i, i)]
print(showList)
if __name__ == '__main__':
A = [1,2,-4,7,3,-5,6,11,-20,9,14,15,5,2,-8]
if __name__ == "__main__":
A = [1, 2, -4, 7, 3, -5, 6, 11, -20, 9, 14, 15, 5, 2, -8]
N = 15
segt = SegmentTree(N)
segt.build(1,1,N,A)
print(segt.query(1,1,N,4,6))
print(segt.query(1,1,N,7,11))
print(segt.query(1,1,N,7,12))
segt.update(1,1,N,1,3,111)
print(segt.query(1,1,N,1,15))
segt.update(1,1,N,7,8,235)
segt.build(1, 1, N, A)
print(segt.query(1, 1, N, 4, 6))
print(segt.query(1, 1, N, 7, 11))
print(segt.query(1, 1, N, 7, 12))
segt.update(1, 1, N, 1, 3, 111)
print(segt.query(1, 1, N, 1, 15))
segt.update(1, 1, N, 7, 8, 235)
segt.showData()