data-structures

问题 I need to write a program that counts the number of nodes from a certain level given in binary tree. I mean < numberofnodes(int level){} > I tried writing it without any success because I don't how to get to a certain level then go to count number of nodes. 回答1: Do it with a recursive function which only descends to a certain level. 回答2: Well, there are many ways you can do this. Best is to have a single dimensional array that keep track of the number of nodes that you add/remove at each

问题 I got into problem to solve matrix grouping problem based on its relation. Problem Consider a group of people giving books to each other. More formally, group is composed of all the people who know one another, whether directly to transitively. Example Consider a matrix of input M Input 1100 1110 0110 0001 Output: 2 There are n = 4 people numbered related[0] through related[3]. There are 2 pairs who directly know each other: (related[0], related[1]) and (related[1], related[2]). Because a

问题 I got into problem to solve matrix grouping problem based on its relation. Problem Consider a group of people giving books to each other. More formally, group is composed of all the people who know one another, whether directly to transitively. Example Consider a matrix of input M Input 1100 1110 0110 0001 Output: 2 There are n = 4 people numbered related[0] through related[3]. There are 2 pairs who directly know each other: (related[0], related[1]) and (related[1], related[2]). Because a

问题 I got into problem to solve matrix grouping problem based on its relation. Problem Consider a group of people giving books to each other. More formally, group is composed of all the people who know one another, whether directly to transitively. Example Consider a matrix of input M Input 1100 1110 0110 0001 Output: 2 There are n = 4 people numbered related[0] through related[3]. There are 2 pairs who directly know each other: (related[0], related[1]) and (related[1], related[2]). Because a

问题 Most of sites present this solution(see Method 3 at http://www.geeksforgeeks.org/write-a-function-to-get-the-intersection-point-of-two-linked-lists/ ) 1) Get count of the nodes in first list, let count be c1. 2) Get count of the nodes in second list, let count be c2. 3) Get the difference of counts d = abs(c1 – c2) 4) Now traverse the bigger list from the first node till d nodes so that from here onwards both the lists have equal no of nodes. 5) Then we can traverse both the lists in parallel

问题 Most of sites present this solution(see Method 3 at http://www.geeksforgeeks.org/write-a-function-to-get-the-intersection-point-of-two-linked-lists/ ) 1) Get count of the nodes in first list, let count be c1. 2) Get count of the nodes in second list, let count be c2. 3) Get the difference of counts d = abs(c1 – c2) 4) Now traverse the bigger list from the first node till d nodes so that from here onwards both the lists have equal no of nodes. 5) Then we can traverse both the lists in parallel

问题 Most of sites present this solution(see Method 3 at http://www.geeksforgeeks.org/write-a-function-to-get-the-intersection-point-of-two-linked-lists/ ) 1) Get count of the nodes in first list, let count be c1. 2) Get count of the nodes in second list, let count be c2. 3) Get the difference of counts d = abs(c1 – c2) 4) Now traverse the bigger list from the first node till d nodes so that from here onwards both the lists have equal no of nodes. 5) Then we can traverse both the lists in parallel

问题 I have a list of dictionaries that I would like to filter based on multiple criteria. A shortened version of the list looks like so: orders = [{"name": "v", "price": 123, "location": "Mars"}, {"name": "x", "price": 223, "location": "Mars"}, {"name": "x", "price": 124, "location": "Mars"}, {"name": "y", "price": 456, "location": "Mars"}, {"name": "z", "price": 123, "location": "Mars"}, {"name": "z", "price": 5623, "location": "Mars"}] I am looking to end up with a list that contains the

问题 I have a list of dictionaries that I would like to filter based on multiple criteria. A shortened version of the list looks like so: orders = [{"name": "v", "price": 123, "location": "Mars"}, {"name": "x", "price": 223, "location": "Mars"}, {"name": "x", "price": 124, "location": "Mars"}, {"name": "y", "price": 456, "location": "Mars"}, {"name": "z", "price": 123, "location": "Mars"}, {"name": "z", "price": 5623, "location": "Mars"}] I am looking to end up with a list that contains the

问题 I'm using Heap's algorithm to create a list-of-lists containing each permutation of said list. Each permutation will be its own list. It works properly when I print it within the algorithm, but it doesn't work properly when I try to add it to my list-of-lists and they are all the same array (4, 1, 2, 3). I commented out the print that I tested to make sure it was working. My current code: public static ArrayList<int[]> lists = new ArrayList<>(); public static void main(String[] args) { int[]