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from cmath import inf class Solution: def cost(self, s: str, low: int, high: int): ss = list(s[low: high]) re_ss = ss[::-1] cos = 0 for i in range(len 阅读全文
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ref: https://www.zybuluo.com/hanbingtao/note/476663 https://zybuluo.com/hanbingtao/note/541458 阅读全文
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保持栈的单调，只有栈为空或比栈顶大/小的元素才可入栈，否则出栈直到满足条件 In order to keep the stack monotonic, only when the stack is empty or the top element of the stack is smaller/bi 阅读全文
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Altough it sounds quiet like KNN algorithm, however, KNN is a kind of classification algorithm of supervised learning while K MEANS is a kind of unsup 阅读全文
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if you don't have right to wirte file or mkdir in /System/Library/Frameworks/JavaVM.framework/Libraries then, do as following: restart your mac, press 阅读全文
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if you meet error like this: java.io.IOException: META-INF : could not create directory at sun.tools.jar.Main.extractFile(Main.java:1050) at sun.tools 阅读全文
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Simply, in summary, error is related to the partial derivative (z) of cost function (C), so it can be write as the derivative of the composite funtion 阅读全文
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RRT is a random search algorithm, used to find a path from the start point to the target. it can be describe like:(pseudo code) while the termination 阅读全文
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Python provides generator functions as a convenient shortcut to building iterators. # a generator that yields items instead of returning a list def fi 阅读全文
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use an algorithm to separate the letters from sentences. ( kind of classifier) the architecture of neural networks: input layer; hidden layer; output 阅读全文