浙江大学PAT_甲级_1094. The Largest Generation (25)

题目链接：点击打开链接

A family hierarchy is usually presented by a pedigree tree where all the nodes on the same level belong to the same generation. Your task is to find the generation with the largest population.

Input Specification:

Each input file contains one test case. Each case starts with two positive integers N (<100) which is the total number of family members in the tree (and hence assume that all the members are numbered from 01 to N), and M (<N) which is the number of family members who have children. Then M lines follow, each contains the information of a family member in the following format:

ID K ID[1] ID[2] ... ID[K]

where ID is a two-digit number representing a family member, K (>0) is the number of his/her children, followed by a sequence of two-digit ID's of his/her children. For the sake of simplicity, let us fix the root ID to be 01. All the numbers in a line are separated by a space.

Output Specification:

For each test case, print in one line the largest population number and the level of the corresponding generation. It is assumed that such a generation is unique, and the root level is defined to be 1.

Sample Input:

23 1321 1 2301 4 03 02 04 0503 3 06 07 0806 2 12 1313 1 2108 2 15 1602 2 09 1011 2 19 2017 1 2205 1 1107 1 1409 1 1710 1 18

Sample Output:

9 4

给了一棵树，求出结点最多的一层的结点数量和这一层的层数

用二维动态数组表示树，然后层序遍历，计算最大节点数和层数

#include<iostream> #include<vector>#include<queue>using namespace std;vector<vector<int>> family(101);//用二维动态数组代替树void input(){int i=0,tempid = 0;//tempid孩子结点的编号int id, k ;//id某人的编号，h一个人的孩子数量cin >> id >> k;for (i = 0; i < k; i++){cin >> tempid;family[id].push_back(tempid);//把孩子代号添加进树 }}void bfs()//树的层序遍历{int max = 1, level = 1;//max最多一代的人数，level人数最多的第几代人int size, generation=level ,root=1;//size某代的人数即树的某层的结点数 , level第几代人即树的层数queue<int>Q;Q.push(root);while (!Q.empty()){size = Q.size();if (size > max){max= size;//记录最多人数level =generation;//记录最多人数在第几代}while (size--){root = Q.front();Q.pop();for (auto i : family[root]){Q.push(i);}}generation++;//层数+1}cout << max<< ' ' <<level;//输出某代最多的人数，和第level代}int main(){int n, m; //n家庭总人数，m有孩子的人数cin >> n >> m;for (int i = 0; i < m; i++){input();}bfs();//system("pause");return 0;}