PAT 甲级 1004 Counting Leaves

1004 Counting Leaves （30 point(s)）

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

Input Specification:

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.

The input ends with N being 0. That case must NOT be processed.

Output Specification:

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

Experiential Summing-up

emmmm  This question involve level order traversal and the structure of tree. The difficulty is little~So much for that~

(The purpose of using English to portray my solution is that to exercise the ability of my expression of English and accommodate PAT advanced level's style.We can make progress together by reading and comprehending it. Please forgive my basic grammar's and word's error. Of course, I would appreciated it if you can point out my grammar's and word's error in comment section.( •̀∀•́ ) Furthermore, Big Lao please don't laugh at me because I just a English beginner settle for CET6    _(:з」∠)_  )

Accepted Code

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <queue>
using namespace std;
const int maxn=110;
const int INF=0x3fffffff;
int level[maxn];
struct Node
{
	int child[maxn];
	int c_num;
	int level;
	Node()
	{
		memset(child,0,sizeof(child));
		c_num=0;
	}
}Tree[maxn];
int level_order()
{
	memset(level,0,sizeof(level));
	queue<Node> q;
	Tree[1].level=0;
	q.push(Tree[1]);
	int maxlevel=-1;
	while(q.size())
	{
		Node a=q.front();
		q.pop();
		if(a.level>maxlevel)
			maxlevel=a.level;
		if(a.c_num==0)
			++level[a.level];
		else
			for(int i=0;i<a.c_num;++i)
			{
				Tree[a.child[i]].level=a.level+1;
				q.push(Tree[a.child[i]]);
			}
	}
	return maxlevel;
}
int main()
{
	int m,n,t,id;
    scanf("%d %d",&n,&m);
	for(int i=0;i<m;++i)
	{
		scanf("%d %d",&id,&t);
		Tree[id].c_num=t;
		for(int j=0;j<t;++j)
			scanf("%d",&Tree[id].child[j]);
	}
	int num=level_order();
	for(int i=0;i<=num;++i)
	{
		printf("%d%c",level[i],i==num?'\n':' ');
	}
	return 0;
}