求助PAT:ZigZagging on a Tree

[USS Enterprise-E]

#include <stdio.h>

typedef int ElementType;

typedef struct TreeNode *Tree;
struct TreeNode
{
	ElementType Element;
	Tree Left;
	Tree Right;
	int Flag;
};

#define MAXN 30

Tree CreateNode(ElementType X);
Tree CreateTree(ElementType *InOrder, ElementType *PostOrder, int N, int cnt);
void LevelOrder(Tree T);

int Num=0;

int main()
{
	int N;
	ElementType InOrder[MAXN], PostOrder[MAXN];
	Tree BinaryTree;
	int i;

	scanf("%d", &N);

	Num = N;

	for (i = 0; i < N; i++)
		scanf("%d", &InOrder[i]);

	for (i = 0; i < N; i++)
		scanf("%d", &PostOrder[i]);

	BinaryTree = CreateTree(InOrder, PostOrder, N, 1);

	LevelOrder(BinaryTree);

	system("pause");
	return 0;
}

Tree CreateNode(ElementType X)
{
	Tree T;

	T = (Tree)malloc(sizeof(struct TreeNode));

	T->Element = X;

	T->Left = NULL;
	T->Right = NULL;

	return T;
}

Tree CreateTree(ElementType *InOrder, ElementType *PostOrder, int N, int cnt)
{
	Tree T;
	ElementType InTreeLeft[MAXN], InTreeRight[MAXN], PostTreeLeft[MAXN], PostTreeRight[MAXN];
	int i, j, k = 0;
	int N_Left, N_Right;

	if (N == 0)
		return NULL;
	else
	{
		T = CreateNode(PostOrder[N - 1]);
		T->Flag = cnt;
		if (N != 1)
		{
			for (i = 0; InOrder[i] != PostOrder[N - 1]; i++)
				InTreeLeft[i] = InOrder[i];

			for (j = i + 1; j < N; j++)
				InTreeRight[k++] = InOrder[j];

			N_Left = i;
			N_Right = k;

			for (i = 0; PostOrder[i] != InTreeRight[0]; i++)
				PostTreeLeft[i] = PostOrder[i];

			k = 0;
			for (j = i; j < N - 1; j++)
				PostTreeRight[k++] = PostOrder[j];

			cnt++;
			T->Left = CreateTree(InTreeLeft, PostTreeLeft, N_Left, cnt);
			T->Right = CreateTree(InTreeRight, PostTreeRight, N_Right, cnt);
		}

		return T;
	}
}

void LevelOrder(Tree T)
{
	int result[30][16] = { 0 };
	Tree TreeNow;
	Tree Queue[30];
	int Front=0, Rear=0;
	int i[30] = { 0 };
	int j, k, l = 0;
	int cnt = 1;

	Queue[Rear++] = T;
	//当队头和队尾相等时，表示队列为空
	while (Front < Rear)
	{
		//队头结点出队
		TreeNow = Queue[Front++];

		result[TreeNow->Flag - 1][i[TreeNow->Flag - 1]] = TreeNow->Element;
		i[TreeNow->Flag - 1]++;

		//将队头结点的左右孩子依次入队
		if (TreeNow->Left != NULL) 
		{
			Queue[Rear++] = TreeNow->Left;
		}
		if (TreeNow->Right != NULL) 
		{
			Queue[Rear++] = TreeNow->Right;
		}
	}

	for (j = 0; cnt < Num; j++)
	{
		if (j % 2 != 0)
		{
			for (k = 0; result[j][k]!=0; k++)
			{
				printf("%d", result[j][k]);
				if (cnt < Num)
					printf(" ");
				cnt++;
			}
		}
		else
		{
			while (result[j][l] != 0)
				l++;

			for (k = l - 1; k >= 0; k--)
			{
				printf("%d", result[j][k]);
				if (cnt < Num)
					printf(" ");
				cnt++;
			}
		}
	}
}