Not Only Algorithm,不仅仅是算法,关注数学、算法、数据结构、程序员笔试面试以及一切涉及计算机编程之美的内容 。。
你的位置:NoAlGo博客 » 题解 » 

PAT 1004. Counting Leaves

A family hierarchy is usually presented by a pedigree tree. Your job is to count those family members who have no child.


Each input file contains one test case. Each case starts with a line containing 0 < N < 100, the number of nodes in a tree, and M (< N), the number of non-leaf nodes. Then M lines follow, each in the format:

ID K ID[1] ID[2] … ID[K]
where ID is a two-digit number representing a given non-leaf node, K is the number of its children, followed by a sequence of two-digit ID’s of its children. For the sake of simplicity, let us fix the root ID to be 01.


For each test case, you are supposed to count those family members who have no child for every seniority level starting from the root. The numbers must be printed in a line, separated by a space, and there must be no extra space at the end of each line.

The sample case represents a tree with only 2 nodes, where 01 is the root and 02 is its only child. Hence on the root 01 level, there is 0 leaf node; and on the next level, there is 1 leaf node. Then we should output "0 1" in a line.

Sample Input

2 1
01 1 02

Sample Output

0 1


#include <cstdio>
#include <vector>
using namespace std;

vector<int> tr[101];//树
int cnt[101] = {0}; //每层叶子个数

void DFS(int cur, int lvl)
	if (tr[cur].size() == 0)
		cnt[lvl]++; return;

	for (int i = 0; i < tr[cur].size(); i++)
		DFS(tr[cur][i], lvl+1);

int main()
	int n, m; scanf("%d%d", &n, &m);

	for (int i = 0; i < m; i++)
		int id, k, t; scanf("%d%d", &id, &k);
		while (k--)
			scanf("%d", &t), tr[id].push_back(t);

	DFS(1, 0);

	printf("%d", cnt[0]);
	for (int i = 1, sum = cnt[0]; sum < n - m; sum += cnt[i++])
		printf(" %d", cnt[i]);

	return 0;
上一篇: 下一篇: