binary-search

How can I use std::binary_search using just a key?

不想你离开。 提交于 2019-12-21 17:07:05
问题 I have some data that is stored in a sorted vector. This vector is sorted by some key. I know the STL has an algorithm for checking if an element is in this sorted list. This means I can write something like this: struct MyData { int key; OtherData data; }; struct MyComparator { bool operator()( const MyData & d1, const MyData & d2 ) const { return d1.key < d2.key; } }; bool isKeyInVector( int key, const std::vector<MyData> &v ) { MyData thingToSearchFor; thingToSearchFor.key = key; return

Recursive binary search method having only 2 arguments

孤者浪人 提交于 2019-12-21 09:36:52
问题 Okay so this is for a school assignment. I have had no problems doing a recursive binary search but the assignment specifically says that the method should only take 2 arguments, the list, and the item you are searching for. This is where I am getting a little lost. public int binarySearch(List<Card> cards, Card key) { int mid = (cards.size()) / 2; if(cards.size() == 1) { if(key.equals(cards.get(0))) { return 0; } } else { if(key.equals(cards.get(mid))) { return mid; } else if(key.compareTo

Complexity of Binary Search

佐手、 提交于 2019-12-21 04:53:12
问题 I am watching the Berkley Uni online lecture and stuck on the below. Problem : Assume you have a collection of CD that is already sorted. You want to find the list of CD with whose title starts with "Best Of." Solution : We will use binary search to find the first case of "Best Of" and then we print until the tile is no longer "Best Of" Additional question : Find the complexity of this Algorithm. Upper Bound : Binary Search Upper Bound is O(log n), so once we have found it then we print let

Complexity of Binary Search

こ雲淡風輕ζ 提交于 2019-12-21 04:52:10
问题 I am watching the Berkley Uni online lecture and stuck on the below. Problem : Assume you have a collection of CD that is already sorted. You want to find the list of CD with whose title starts with "Best Of." Solution : We will use binary search to find the first case of "Best Of" and then we print until the tile is no longer "Best Of" Additional question : Find the complexity of this Algorithm. Upper Bound : Binary Search Upper Bound is O(log n), so once we have found it then we print let

Find the smallest number that is greater than a given number in a sorted list

感情迁移 提交于 2019-12-20 20:16:09
问题 Given a sorted list of numbers, I need to find the smallest number that is greater than a given number. Consider this list: arr=[1,2,3,5,7,11,101,131,151,181,191,313,353,373,383] Say the specified number is 320. Then, my method should return 353 as 353 is the smallest number greater than 320. I am trying to use a slightly modified form of binary search; however on execution the program goes into infinite loop. def modBinarySearch(arr,x): l=len(arr) mid=l/2 if arr[mid]>=x and arr[mid-1]<x:

Parallel Binary Search

浪尽此生 提交于 2019-12-20 10:54:29
问题 I'm just starting to learn about parallel programming, and I'm looking at binary search. This can't really be optimized by throwing more processors at it right? I know it's supposedly dividing and conquering, but you're really "decreasing and conquering" (from Wikipedia). Or could you possibly parallelize the comparisons? (if X is less than array[mid] , search from low to mid - 1 ; else if X is greater than array[mid] search from mid + 1 to high , else return mid , the index of X ) Or how

Binary Search to Compute Square root (Java)

不问归期 提交于 2019-12-20 10:35:21
问题 I need help writing a program that uses binary search to recursively compute a square root (rounded down to the nearest integer) of an input non-negative integer. This is what I have so far: import java.util.Scanner; public class Sqrt { public static void main(String[] args) { Scanner console = new Scanner(System.in); System.out.print("Enter A Valid Integer: "); int value = console.nextInt(); calculateSquareRoot(value); } public static int calculateSquareRoot(int value) { while (value > 0) {

<algorithm> function for finding last item less-than-or-equal to, like lower_bound

早过忘川 提交于 2019-12-20 08:56:29
问题 Is there a function in that uses binary search, like lower_bound but that returns the last item less-than-or-equal-to according to a given predicate? lower_bound is defined to: Finds the position of the first element in an ordered range that has a value greater than or equivalent to a specified value, where the ordering criterion may be specified by a binary predicate. and upper_bound : Finds the position of the first element in an ordered range that has a value that is greater than a

Median of a Matrix with sorted rows

北战南征 提交于 2019-12-20 08:49:58
问题 I am not able to solve the following problem optimally nor finding an approach to do this anywhere. Given a N × M matrix in which each row is sorted, find the overall median of the matrix. Assume N*M is odd. For example, Matrix = [1, 3, 5] [2, 6, 9] [3, 6, 9] A = [1, 2, 3, 3, 5, 6, 6, 9, 9] Median is 5. So, we return 5. Note: No extra memory is allowed. Any help will be appreciated. 回答1: Consider the following process. If we consider the N*M matrix as 1-D array then the median is the element

Difference between binary search and binary search tree?

六眼飞鱼酱① 提交于 2019-12-20 08:22:08
问题 What is the difference between binary search and binary search tree? Are they the same? Reading the internet it seems the second is only for trees (up to 2 children nodes) and binary search doesn't follow this rule. I didn't quite get it. 回答1: Binary Search Trees A node in a binary tree is a data structure that has an element, and a reference to two other binary trees, typically called the left and right subtrees. I.e., a node presents an interface like this: Node: element (an element of some