codevs 3143 二叉树

题目：codevs 3143

思路：就递归解决遍历，用栈和队列也可以做到，但是有简单的何乐而不为；

代码如下：

#include<iostream>#include<cstring>using namespace std;int a[17][2];void prev_travel(int root){if(root == 0) return;cout << root << " ";prev_travel(a[root][0]);prev_travel(a[root][1]);}void mid_travel(int root){if(root == 0) return;mid_travel(a[root][0]);cout << root << " ";mid_travel(a[root][1]);}void order_travel(int root){if(root == 0) return;order_travel(a[root][0]);order_travel(a[root][1]);cout << root << " ";}int main(){int n;cin >> n;for(int i = 1;i <= n;i++){cin >> a[i][0] >> a[i][1];}prev_travel(1);cout << endl;mid_travel(1);cout << endl;order_travel(1);return 0;}