No solution stacks listed in elastic beanstalk configuration

It is how you do the elastic beanstalk configurations. eb init You would be very frustrated when you can select no available solution stacks… Select a solution stack. Available solution stacks are: Select (1 to 0): It is because the credentials you use don’t have administrator rights. Go to Identity and Access Management (IAM) and add…

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Interview Practice Extra 07 – Universal Value Binary Tree

Question Design an algorithm to verify that a tree is a universal value binary tree. Universal value binary tree means all value in that tree is the same. Solution There is two approach for this problem. One is with recursive function and another is with iterative function. For this problem, iterative function makes simpler answer. However,…

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Interview Practice 21 – Summing Combinations

Question Given a integers m and n, generate all combination within 1 to n that would give the sum m. For example, for m=5 and n=5, the combinations are {5}, {4+1}, {3+2}. Solution This is a knapsack problem. # knapsack that store the found combination knapsack = array # find combination of 1..n with sum target…

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Interview Practice Extra 03 – Verify Binary Tree with Same Value

Question Verify whether all nodes have the same value in a binary tree. Solution We can traverse the tree with our usual way, like depth-first or breadth-first algorithm. Then pass a value, probably the root value, to compare with the visiting node. Example # node structure class bst_node: value = None left = None right…

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Interview Practice 15 – Mirror Image of Binary Tree

Question Construct 2 algorithms to make mirror image of any binary tree inputs, one of them using recursive method, another one using looping method. Mirror image means a binary tree that is the horizontal reflection of the original tree. Solution First, to do it in recursive method, we can perform pre-order traversal as usual, see preference….

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Interview Practice 09 – Verify Post-order Sequence of BST

Construct an algorithm to verify if a set of numbers is the post-order search result of a binary search tree.

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Interview Practice 02 – Stack with Minimum Function

定義棧的數據結構,要求添加一個min函數,能夠得到棧的最小元素。要求函數min、push以及pop的時間複雜度都是O(1)。

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