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 or equal to the node's key. The right subtree of a node contains only nodes with keys greater than the node's key. Both the left and right subtrees must also be binary search trees.Insert a sequence of numbers into an initially empty binary search tree. Then you are supposed to count the total number of nodes in the lowest 2 levels of the resulting tree.
Input Specification:
Each input file contains one test case. For each case, the first line gives a positive integer N (<=1000) which is the size of the input sequence. Then given in the next line are the N integers in [-1000 1000] which are supposed to be inserted into an initially empty binary search tree.
Output Specification:
For each case, print in one line the numbers of nodes in the lowest 2 levels of the resulting tree in the format:
n1 + n2 = n
where n1 is the number of nodes in the lowest level, n2 is that of the level above, and n is the sum.
Sample Input: 9 25 30 42 16 20 20 35 -5 28 Sample Output:2 + 4 = 6
建一个带深度的二叉搜索树就行了
#include <iostream> #include <stdio.h> #include <stdlib.h> #include <vector> using namespace std; typedef struct Node *Tree; struct Node { int Element; int depth; Tree Left; Tree Right; }; static int count; int max1=0; int qq[2]; Tree Insert(int x, Tree T) { if(T==NULL){ T=(Node *)malloc(sizeof(struct Node)); T->Element=x; T->Left=NULL; T->Right=NULL; T->depth=count; } else if(x<=T->Element) { count++; T->Left=Insert(x,T->Left); } else if(x>T->Element){ count++; T->Right=Insert(x,T->Right); } if(count>max1) max1=count; return T; } void get(Tree T); int main() { Tree C=NULL; int a; cin >> a; for(int i=0;i<a;i++){ int b; cin >> b; count=0; C=Insert(b,C); } qq[0]=0; qq[1]=0; get(C); cout << qq[0] <<" + "<< qq[1]<< " = "<< qq[0]+qq[1]; return 0; } void get(Tree T) { if(T->depth==max1) qq[0]++; if(T->depth==(max1-1)) qq[1]++; if(T->Left!=NULL) get(T->Left); if(T->Right!=NULL) get(T->Right); }