IT公司100题-tencent-打印所有高度为2的路径

  1 #include <iostream>
  2 #include "../utility/printCollection.h"
  3 using namespace std;
  4 
  5 struct bsnode{
  6     int data;
  7     bsnode* left;
  8     bsnode* right;
  9 };
 10 
 11 void add_bsnode(bsnode* &root, int value)
 12 {
 13     if(root == NULL)
 14     {
 15         bsnode* tmp = new bsnode();
 16         tmp->data = value;
 17         tmp->left = NULL;
 18         tmp->right = NULL;
 19         root = tmp;
 20         return;
 21     }
 22     if(value > root->data)
 23         add_bsnode(root->right, value);
 24     else if(value < root->data)
 25         add_bsnode(root->left, value);
 26     else
 27         cout << "duplicate value" << endl;
 28 }
 29 
 30 void print_tree(bsnode* root)
 31 {
 32     if(root == NULL)
 33         return;
 34     if(root->left != NULL)
 35         print_tree(root->left);
 36     cout << root->data << " ";
 37     if(root->right != NULL)
 38         print_tree(root->right);
 39 }
 40 
 41 
 42 void check_node(bsnode* root, int n, int &depth, vector<int> &path)
 43 {
 44     //如果当前深度>n，不需要继续访问
 45     if(depth > n || root == NULL)
 46         return;
 47 
 48     //检查前压栈当前节点，depth+1
 49     path.push_back(root->data);
 50     depth++;
 51 
 52     //如果当前深度=n
 53     if(depth == n)
 54         if(root->left == NULL && root->right == NULL)
 55         {
 56             cout << "path found: " << endl;
 57             printCollection(path);
 58             cout << endl;            
 59         }
 60 
 61     //如果当前深度<n
 62     if(depth < n)
 63         if(root->left != NULL)
 64             check_node(root->left, n, depth, path);
 65         if(root->right != NULL)
 66             check_node(root->right, n, depth, path);
 67 
 68     //检查完出栈当前节点，depth-1
 69     path.pop_back();
 70     depth--;
 71     return;
 72 }
 73 
 74 void print_node(bsnode* root, int n)
 75 {
 76     if(root == NULL)
 77         return;
 78 
 79     //每次检查前重定义depth
 80     int depth = -1;
 81     vector<int> path;
 82 
 83     //每次检查前clear path
 84     path.clear();
 85 
 86     //检查当前节点的所有叶子节点的高度
 87     check_node(root, n, depth, path);
 88     
 89     //递归检查左子树
 90     print_node(root->left, n);
 91     //递归检查右子树
 92     print_node(root->right, n);
 93 }
 94 
 95 
 96 int main()
 97 {
 98     bsnode* root = NULL;
 99     add_bsnode(root, 10);    
100     add_bsnode(root, 6);
101     add_bsnode(root, 16);
102     add_bsnode(root, 4);
103     add_bsnode(root, 8);
104     add_bsnode(root, 14);
105     add_bsnode(root, 18);
106     add_bsnode(root, 2);
107     add_bsnode(root, 5);
108     add_bsnode(root, 12);
109     add_bsnode(root, 15);
110     add_bsnode(root, 20);
111     add_bsnode(root, 11);
112 
113     cout << "Tree content: " << endl;
114     print_tree(root);
115     cout << endl << endl;
116 
117     int height = 2; 
118     cout << "Nodes that with height " << height << " are:" << endl;
119     print_node(root, height);
120     cout << endl;
121 }

$ ./a.exe
Tree content:
2 4 5 6 8 10 11 12 14 15 16 18 20

Nodes that with height 2 are:
path found:
[10 6 8]

path found:
[6 4 2]

path found:
[6 4 5]

path found:
[16 14 15]

path found:
[16 18 20]

path found:
[14 12 11]