[数据结构学习日记]File Transfer

最新推荐文章于 2024-07-19 23:30:29 发布

原创最新推荐文章于 2024-07-19 23:30:29 发布 · 356 阅读

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#数据结构 #学习 #蓝桥杯

本文探讨在一个由双向连接组成的网络中，如何判断任意两台电脑间能否进行文件传输。通过输入连接信息和查询请求，算法实现网络连通性和组件划分。

We have a network of computers and a list of bi-directional connections. Each of these connections allows a file transfer from one computer to another. Is it possible to send a file from any computer on the network to any other?

Input Specification:

Each input file contains one test case. For each test case, the first line contains N (2≤N≤104), the total number of computers in a network. Each computer in the network is then represented by a positive integer between 1 and N. Then in the following lines, the input is given in the format:

I c1 c2

where I stands for inputting a connection between c1 and c2; or

C c1 c2

where C stands for checking if it is possible to transfer files between c1 and c2; or

where S stands for stopping this case.

Output Specification:

For each C case, print in one line the word "yes" or "no" if it is possible or impossible to transfer files between c1 and c2, respectively. At the end of each case, print in one line "The network is connected." if there is a path between any pair of computers; or "There are k components." where k is the number of connected components in this network.

Sample Input 1:

Sample Output 1:

no
no
yes
There are 2 components.

Sample Input 2:

Sample Output 2:

no
no
yes
yes
The network is connected.

#include <iostream>
using namespace std;
int Find(int* Set, int num) {
	if (Set[num] < 0) {
		return num;
	}
	else {
		return Set[num] = Find(Set, Set[num]);
	}
}
void Union(int* Set, int num1, int num2) {
	int root1 = Find(Set, num1);
	int root2 = Find(Set, num2);
	if (Set[root1] > Set[root2]) {
		Set[root2] = Set[root1] + Set[root2];
		Set[root1] = root2;
	}
	else {
		Set[root1] = Set[root1] + Set[root2];
		Set[root2] = root1;
	}
}
int main() {
	int N;
	cin >> N;
	int* Set = new  int[N + 1];
	for (int i = 0; i < N + 1; i++) {
		Set[i] = -1;
	}
	char op;
	int num1, num2;
	cin >> op;
	while (op != 'S') {
		cin >> num1 >> num2;
		if (op == 'I') {
			Union(Set, num1, num2);
		}
		else if (op == 'C') {
			if (Find(Set, num1) == Find(Set, num2)) {
				cout << "yes" << endl;
			}
			else {
				cout << "no" << endl;
			}
		}
		cin >> op;
	}
	int cnt = 0;
	for (int i = 1; i < N + 1; i++) {
		if (Set[i] < 0) cnt++;
	}
	if (cnt == 1) {
		cout << "The network is connected." << endl;
	}
	else {
		cout << "There are " << cnt << " components." << endl;
	}
	return 0;
}