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123 lines
3.3 KiB
Python
123 lines
3.3 KiB
Python
''' mbinary
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#########################################################################
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# File : winnerTree.py
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# Author: mbinary
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# Mail: zhuheqin1@gmail.com
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# Blog: https://mbinary.xyz
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# Github: https://github.com/mbinary
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# Created Time: 2018-05-19 23:06
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# Description:
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#########################################################################
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'''
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class winnerTree:
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'''if i<lowExt p = (i+offset)//2
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else p = (i+n-1-lowExt)//2
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offset is a num 2^k-1 just bigger than n
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p is the index of tree
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i is the index of players
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lowExt is the double node num of the lowest layer of the tree
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'''
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def __init__(self, players, reverse=False):
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self.n = len(players)
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self.tree = [0]*self.n
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players.insert(0, 0)
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self.players = players
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self.reverse = reverse
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self.getNum()
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self.initTree(1)
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def getNum(self):
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i = 1
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while 2*i < self.n:
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i = i*2
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if 2*i == self. n:
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self.lowExt = 0
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self.s = 2*i-1
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else:
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self.lowExt = (self.n-i)*2
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self.s = i-1
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self.offset = 2*i-1
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def treeToArray(self, p):
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return 2*p-self.offset if p > self.s else 2*p+self.lowExt-self.n+1
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def arrayToTree(self, i):
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return (i+self.offset)//2 if i <= self.lowExt else (i-self.lowExt + self.n-1)//2
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def win(self, a, b):
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return a < b if self.reverse else a > b
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def initTree(self, p):
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if p >= self.n:
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delta = p % 2 # !!! good job notice delta mark the lchild or rchlid
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return self.players[self.treeToArray(p//2)+delta]
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l = self.initTree(2*p)
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r = self.initTree(2*p+1)
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self.tree[p] = l if self.win(l, r) else r
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return self.tree[p]
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def winner(self):
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idx = 1
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while 2*idx < self.n:
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idx = 2*idx if self.tree[2*idx] == self.tree[idx] else idx*2+1
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num = self.treeToArray(idx)
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num = num+1 if self.players[num] != self.tree[1] else num
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return self.tree[1], num
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def getOppo(self, i, x, p):
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oppo = None
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if 2*p < self.n:
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oppo = self.tree[2*p]
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elif i <= self.lowExt:
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oppo = self.players[i-1+i % 2*2]
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else:
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lpl = self.players[2*p+self.lowExt-self.n+1]
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oppo = lpl if lpl != x else self.players[2*p+self.lowExt-self.n+2]
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return oppo
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def update(self, i, x):
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''' i is 1-indexed which is the num of player
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and x is the new val of the player '''
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self.players[i] = x
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p = self.arrayToTree(i)
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oppo = self.getOppo(i, x, p)
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self.tree[p] = x if self.win(x, oppo) else oppo
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p = p//2
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while p:
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l = self.tree[p*2]
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r = None
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if 2*p+1 < self.n:
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r = self.tree[p*2+1] # notice this !!!
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else:
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r = self.players[2*p+self.lowExt-self.n+1]
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self.tree[p] = l if self.win(l, r) else r
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p = p//2
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if __name__ == '__main__':
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s = [4, 1, 6, 7, 9, 5234, 0, 2, 7, 4, 123]
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t = winnerTree(s)
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print(t.players, t.tree)
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for i in s:
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val, idx = t.winner()
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print(val, idx)
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t.update(idx, -1)
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'''
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[0, 4, 1, 6, 7, 9, 5234, 0, 2, 7, 4, 123] [0, 5234, 5234, 123, 7, 5234, 7, 123, 4, 7, 5234]
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5234 6
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123 11
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9 5
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7 4
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7 9
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6 3
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4 1
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4 10
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2 8
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1 2
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'''
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