谁能告诉我这里指的是什么“节点”以及示例测试用例是如何工作的？ 数组中边的确切含义是什么？

Question

Write a program that does the following: Accept the following inputs: (1) Number of nodes (2) A 2-D array representing edges. ith edge connects node input2[0][i] to node input2[1][i]. Assuming that a line can be drawn between nodes if there is an edge between them, print number of lines that can be drawn between nodes.

Sample test case: input1: 4 input2: {{1,1,1},{2,3,4}} output1: 3

Answer 1

This looks like a way to represent a directed graph. The number of nodes implies a set of nodes number from 1 to input1 . input2 then appears to be a two-element list. Each element of input2[0] represents the starting point of an edge, and each corresponding element of input2[1] represents the end point. In your example, there are 4 nodes (1, 2, 3, 4), with edges connecting node 1 to each of nodes 2, 3, and 4.

                      * 4
                      ^
                      |
                      |
                      | 
                    1 * --------> * 2
                      |
                      |
                      |
                      v
                      * 3

                     

The output is 3 because the contents of input2 represents the three edges shown in the diagram.