Algorithm
Question Given a number, find the number of 1 in the number’s binary expression. For example, binary express of 10 is 1010. So the number of 1 in it is 2. Solution To solve this, we can check each bit by shifting the bits one by one. 1. 1010
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Question Write a program to right-rotate a string by m characters. Right-rotating a string means moving m characters at the left of string to the right. Is it required the time complexity is O(n) and helper memory size is O(1). For example, right-rotate “abcdefghi” by 3 characters gives
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Question Given a function prototype: int continumax(char *output_string,char *input_string). Implement it to find the longest consecutive digits. This function must return the length of the longest digits. The found longest digits should be written to the memory location that output_string is pointing. For example, if
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Question Reverse a linked list. Sample # node structure class Node: value = None next = None def __init__(self, value, next_node=None): self.value = value self.next = next_node # reverse the linked list and return the head node def reverse_linked_list(head): reversed_head = None last_node = None node = head
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Question Consider there are 4 blue and 4 red cards. Host gets 2 cards randomly, no one knows what cards they are. Then he places 2 random cards at the forehead of each player A, B and C. Players do not know the color of their own cards, but know
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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
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Question You have 9 marbles. 8 marbles weigh 1 ounce each, & one marble weighs 1.5 ounces. You are unable to determine which is the heavier marble by looking at them. You have a weighing scale that consists of 2 pans, but the scale is only good for 2
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Question Convert the inputted string to an integer. For example, “345” will output 345. Solution Though it looks simple, in fact it is pretty tricky. First we need to make the concept clear. 1. Scan each character from the left to right, then multiply the previously obtained integer by ten
Algorithm
Question Construct an algorithm so that the Nth item of Fibonacci Sequence can be found in the shortest time. Definition of Fibonacci Sequence is: f(n) = 0 , when n = 0 f(n) = 1 , when n = 1 f(n) = f(n-1) + f(n-2), when n > 1 Solution There are many
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Consider Consider there is a list containing N numbers, and which formed a ring. That is, item n+1 is item 1. Construct an algorithm such that it traverses through the ring, and remove the Mth item. Repeat this process until there is only one number left in the ring
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Question Given a string, write an algorithm to find the character inside that appeared only once. For example, the result for string “abaccdeff” is b. Solution We can use a hashtable to count the appearance times for each character. Then rescan the hashtable for the character that appeared only once.
Algorithm
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