algorithm

All possible combination of N numbers to sum X

て烟熏妆下的殇ゞ 提交于 2021-02-08 12:01:18
问题 I have to write a program that given n , target and max , returns all the number combinations of size n that sums to target , where no number can be greater than max Example: target = 3 max = 1 n = 4 Output: [0, 1, 1, 1] [1, 0, 1, 1] [1, 1, 0, 1] [1, 1, 1, 0] It is a very simple example, but there can be a very large set of possible combinations for a more complex case. I'm looking for any algorithmic clue, but a Java implementation would be perfect. 回答1: Here a java version: import java.util

All possible combination of N numbers to sum X

自闭症网瘾萝莉.ら 提交于 2021-02-08 12:01:17
问题 I have to write a program that given n , target and max , returns all the number combinations of size n that sums to target , where no number can be greater than max Example: target = 3 max = 1 n = 4 Output: [0, 1, 1, 1] [1, 0, 1, 1] [1, 1, 0, 1] [1, 1, 1, 0] It is a very simple example, but there can be a very large set of possible combinations for a more complex case. I'm looking for any algorithmic clue, but a Java implementation would be perfect. 回答1: Here a java version: import java.util

Understanding the Shortest Job First Algorithm (Non-preemptive)

。_饼干妹妹 提交于 2021-02-08 11:52:11
问题 The shortest job first algorithm is shown in the following image: If it is shortest job first/shortest process next, shouldn't the order be: P1 → P5 → P3 → P4 → P2 ? Since that's the order of lowest to highest service times. Why does process 2 come second? I know if we use burst times instead, that would be the order, but I have no idea what the differences between service time and burst times are. Any help would be much appreciated explaining that graphic. 回答1: The image in the question

how to calculate XOR (dyadic) convolution with time complexity O(n log n)

烂漫一生 提交于 2021-02-08 11:46:16
问题 enter image description here “⊕” is the bitwise XOR operation. I think Karatsuba’s algorithm may be used to solve the problem, but when I try to use XOR instead of "+" in the Karatsuba’s algorithm, it is tough to get the sub-problem. 回答1: The convolution theorem gives you F(C) = F(A) . F(B) where F is a Fourier-related transform, in this case the Hadamard transform, and . is point-wise multiplication. Using the fast Walsh–Hadamard transform, you can compute F(A) , F(B) , and finally C (using

Merge K sorted arrays

浪尽此生 提交于 2021-02-08 11:20:37
问题 I am given k sorted arrays and need to merge them into one sorted array. We are assuming that n is the total number of elements in all the input arrays and that k=3. public class Merge { // Create a mergeklists() to merge 3 sorted arrays into one sorted array // Input: 3 sorted arrays a1[], a2[], a3[] // Output: one sorted array a[] that contains all the elements from input arrays public static void merge3lists(int[] a1, int[] a2, int[] a3, int[] a) { int i=0; int j=0; int h=0; int n = a1

Why is my sorting algorithm not sorting correctly?

假装没事ソ 提交于 2021-02-08 11:05:37
问题 I was given this sorting function in the best answer to a question I posted. It worked on the example data, but does not appear to work on my actual data and I am not sure why. My data can be see here: JSON It's an object of objects like this: "Montana": { "superiors": [ "Massachusetts", "Oklahoma", "New Mexico" ], "inferiors": [ "North Carolina" ] } It exists to instruct the sorting function. Here, Montana must be higher up in the list than North Carolina . But below Massachusetts , Oklahoma

Which node go in left or right on addition of weight while huffman tree creation

大憨熊 提交于 2021-02-08 10:59:47
问题 I am trying to create a Huffman tree and i am bit confused by reading several links on internet. Some add the greater(in terms of weight) child nodes in left or some on right. So my question: (1)Is it really a matter that where to add the nodes(in left or right) ? (2) May i add node with greater weight in right or lower weight in Left ? Thanks for the help. 回答1: As long as you're consistent, it makes no difference. Either you put all the lower weights on left children and all the higher

Which node go in left or right on addition of weight while huffman tree creation

◇◆丶佛笑我妖孽 提交于 2021-02-08 10:57:29
问题 I am trying to create a Huffman tree and i am bit confused by reading several links on internet. Some add the greater(in terms of weight) child nodes in left or some on right. So my question: (1)Is it really a matter that where to add the nodes(in left or right) ? (2) May i add node with greater weight in right or lower weight in Left ? Thanks for the help. 回答1: As long as you're consistent, it makes no difference. Either you put all the lower weights on left children and all the higher

Which sorting algorithm uses the fewest number of comparisons while elements are being added?

落花浮王杯 提交于 2021-02-08 10:48:35
问题 I have a lot of music and i want to rank them from least favorite to favorite (this will take many days). I would like to compare two music files at a time (2-way comparison). I saw some questions on algorithms with the fewest comparisons. But the catch is that (since it's a long process) i want to add new music to the collection and in that case i don't want to start over sorting everything (thus creating a lot more comparison steps). Which algorithm has the least amount of comparisons while

number of substring which are whose anagrams are palindrome

落花浮王杯 提交于 2021-02-08 10:48:33
问题 Given a string of digits, count the number of subwords (consistent subsequences) that are anagrams of any palindrome. My attempt in Python: def ispalin(s): if len(s)%2==0: for i in s: if s.count(i)%2!=0: return False else: sum =0 for i in set(s): if s.count(i)%2==1: sum = sum+1 if sum == 1: return True else: return False return True def solution(S): # write your code in Python 3.6 count=len(S) for i in range(len(S)): for j in range(i+1,len(S)): if ispalin(S[i:j+1]): count=count+1 return count