1 #include <bits/stdc++.h> 2 using namespace std; 3 typedef int ElemType; 4 5 typedef struct Node{ 6 ElemType data; 7 Node* lson; 8 Node* rson; 9 Node(ElemType data, Node* lson, Node* rson) { 10 this->data = data; 11 this->lson = lson; 12 this->rson = rson; 13 } 14 }*Tree; 15 16 int get_kth_number(Tree T,int k){ 17 queue<Tree>q; 18 q.push(T); 19 int h=1,ans=0; 20 Tree r=T; 21 while(!q.empty()){ 22 Tree p=q.front(); 23 q.pop(); 24 if(p->lson)q.push(p->lson); 25 if(p->rson)q.push(p->rson); 26 if(h==k)ans++; 27 if(p==r){ 28 if(h==k)break; 29 r=q.back(); 30 h++; 31 ans=0; 32 } 33 } 34 return ans; 35 } 36 37 38 int main(){ 39 Node* v7 = new Node(7, NULL, NULL); 40 Node* v1 = new Node(1, NULL, NULL); 41 Node* v3 = new Node(3, NULL, NULL); 42 Node* v2 = new Node(2, v1, v3); 43 Node* v5 = new Node(5, NULL, NULL); 44 Node* v6 = new Node(6, v5, v7); 45 Node* v4 = new Node(4, v2, v6); 46 47 Tree T=v4; 48 printf("%d",get_kth_number(T,4)); 49 }