A1099 Build A Binary Search Tree

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A Binary Search Tree (BST) is recursively defined as a binary tree which has the following properties:

The left subtree of a node contains only nodes with keys less than the node’s key.
The right subtree of a node contains only nodes with keys greater than or equal to the node’s key.
Both the left and right subtrees must also be binary search trees.
Given the structure of a binary tree and a sequence of distinct integer keys, there is only one way to fill these keys into the tree so that the resulting tree satisfies the definition of a BST. You are supposed to output the level order traversal sequence of that tree. The sample is illustrated by Figure 1 and 2.

Input Specification:
Each input file contains one test case. For each case, the first line gives a positive integer N (≤100) which is the total number of nodes in the tree. The next N lines each contains the left and the right children of a node in the format left_index right_index, provided that the nodes are numbered from 0 to N−1, and 0 is always the root. If one child is missing, then −1 will represent the NULL child pointer. Finally N distinct integer keys are given in the last line.

Output Specification:
For each test case, print in one line the level order traversal sequence of that tree. All the numbers must be separated by a space, with no extra space at the end of the line.

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Sample Input:
9
1 6
2 3
-1 -1
-1 4
5 -1
-1 -1
7 -1
-1 8
-1 -1
73 45 11 58 82 25 67 38 42
Sample Output:
58 25 82 11 38 67 45 73 42

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#include<bits/stdc++.h>
using namespace std;
int n;
#define MAX 110
int in[MAX],num[MAX];
struct node{
	int v;
	int l,r;
};
node tree[MAX];
bool cmp(int m,int n){
	return m<n;
}
int sum=0;
void inorder(int t){
	if(t==-1) return;
	inorder(tree[t].l);
	tree[t].v=in[sum++];
	inorder(tree[t].r); 
}
void bfs(int r){
	sum=0;
	queue<int> que;
	que.push(r);
	while(!que.empty()){
		int tt=que.front();
		cout<<tree[tt].v;
		sum++;
		if(sum<n) cout<<" ";
		que.pop();
		if(tree[tt].l!=-1) que.push(tree[tt].l);
		if(tree[tt].r!=-1) que.push(tree[tt].r);
		
	}
}
int main(){
	cin>>n;
	for(int i=0;i<n;i++){
		cin>>tree[i].l>>tree[i].r;
	}
	for(int j=0;j<n;j++)
	cin>>in[j];
	sort(in,in+n,cmp);
	inorder(0);	
	bfs(0);
}