\n This article discusses the process of solving an algorithm problem that identifies friendship relationships using C++. The problem involves applying graph theory based on the number of friends and their relationships to understand the friendship network. In this context, we will explore the fundamental concepts of data structures and algorithms, and examine the implementation methods in C++ in detail.\n <\/p>\n
\nProblem:<\/strong> There are N students. Each student has the potential to have friends. The friendship relationship is bidirectional, and given the friendship relationships, implement an algorithm to determine how many friends a specific student has. Additionally, it should be able to check whether two students are friends with each other.\n <\/p>\n \n Input:<\/p>\n \n To solve the problem, we will go through the following steps:<\/p>\n \n To solve the given problem, we need to first model the friendship relationships in the form of a graph. In this case, the vertices of the graph represent students, and the edges represent friendship relationships between those students.\n <\/p>\n \n Therefore, assuming there are N students, we can represent them with integers ranging from 0 to N-1. For example, student A can be represented as 0, and student B as 1.\n <\/p>\n \n We use an adjacency list to represent the graph. We can use a hashmap or vector where each student is a key and the list of students who are friends with that student is the value. Below is a method for constructing the adjacency list in C++:\n <\/p>\n \n In the above code, the \n To count the number of friends of a specific student, we implement a function that returns the size of that student’s adjacency list. Below is an example implementation:\n <\/p>\n \n This code returns the size of the list of friends for a specific student from the adjacency list.\n <\/p>\n \n We also need a function to check whether two students are friends. This function searches through the adjacency list to see if the two students are in the same list of friends. Below is an example implementation:\n <\/p>\n \n The above function checks if student A has student B in their list of friends.\n <\/p>\n \n Now, I will write the complete code incorporating all the explanations given so far:\n <\/p>\n \n In this tutorial, we closely examined the process of solving an algorithm problem that identifies friendship relationships using the C++ language. We learned how to model friendship relationships using important concepts from graph theory and data structures, and how to solve the problem through this modeling. Skills in solving such algorithmic problems are crucial for coding tests for employment, so I encourage you to strengthen your abilities through a variety of problems.\n <\/p>\n <\/body><\/p>\n","protected":false},"excerpt":{"rendered":"\n
Problem Solving Process<\/h2>\n
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1. Graph Modeling<\/h3>\n
2. Constructing an Adjacency List<\/h3>\n
\n#include addFriendship<\/code> function adds a friendship relationship between two students.\n <\/p>\n3. Counting Friends<\/h3>\n
\nint countFriends(int student) {\n return friends[student].size();\n}\n <\/code><\/pre>\n4. Checking Friendship Relationships<\/h3>\n
\nbool areFriends(int a, int b) {\n \/\/ Get A's list of friends\n for (int friend_id : friends[a]) {\n if (friend_id == b) {\n return true; \/\/ Friendship exists\n }\n }\n return false; \/\/ Friendship does not exist\n}\n <\/code><\/pre>\nComplete Code<\/h2>\n
\n#include Conclusion<\/h2>\n