03-树2 List Leaves(C++)

# include <iostream>
# include <cstdio>

struct Node {
    
    
	int left;
	int right;
};
struct Tree {
    
    
	int n;
	int root;
	Node * treeList;

	Tree(int _n) :n(_n)
	{
    
    
		bool isRoot[15];
		for (int i = 0; i < n; ++i) isRoot[i] = true;

		treeList = new Node[n];
		for (int i = 0; i < n; ++i)
		{
    
    
			char b, c;
			scanf("\n%c %c", &b, &c);

			if (b == '-') 
				treeList[i].left = -1;
			else 
				treeList[i].left = b - '0', isRoot[treeList[i].left] = false;


			if (c == '-') 
				treeList[i].right = -1;
			else 
				treeList[i].right = c - '0', isRoot[treeList[i].right] = false;
		}

		root = n;
		while (--root >= 0 && !isRoot[root]);
	}

	void ListLeaves()
	{
    
    
		int queue[100], front = 0, rare = 0;
		queue[++rare] = root;
		int isFirst = true;
		while (front != rare)
		{
    
    
			int deq = queue[++front];
			if (treeList[deq].left != -1) queue[++rare] = treeList[deq].left;
			if (treeList[deq].right != -1) queue[++rare] = treeList[deq].right;
			if (treeList[deq].left == -1 && treeList[deq].right == -1)
			{
    
    
				printf("%s%d", isFirst ? "" : " ", deq); isFirst = false;
			}
		}
	}
};


int main(void)
{
    
    
	int n;
	scanf("%d", &n);
	Tree t(n);

	t.ListLeaves();
	return 0;
}