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Update C2.人间大炮一级准备.md #4

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Update C2.人间大炮一级准备.md #4

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4 changes: 3 additions & 1 deletion C2.人间大炮一级准备.md
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Expand Up @@ -111,6 +111,8 @@

平均来说是n/2，根据概率来说是一半的可能性在前一半就找到了。

#平均应该是n+1/2,n个元素都有1/n的可能是要查找的元素，则检查1个元素、2个元素...n个元素的概率都是1/n，平均就是1*1/n+2*1/n+3*1/n+...+n*1/n=(1+n)/2

最差的情况是n。

不管哪种都是Θ(n)。
Expand Down Expand Up @@ -493,4 +495,4 @@ OK!Done!

我想，原因一是归并排序削去了插入排序中多余的**比较部分**Θ(n^2)，只留下了最小的**比较+移动部分**Θ(nlgn)。

原因二，就是在这个例子中，最聪明的一步是**转化了问题**，把一个寻找数量的问题化为一个排序的问题，可以说是神来之笔，我的脑子还远远不能到达这个地步，可敬可叹！
原因二，就是在这个例子中，最聪明的一步是**转化了问题**，把一个寻找数量的问题化为一个排序的问题，可以说是神来之笔，我的脑子还远远不能到达这个地步，可敬可叹！