题意:给出一个序列,构建二叉搜索树(BST),输出二叉搜索树最后两层的节点个数n1和n2,以及他们的和sum: n1 + n2 = sum 递归建树,然后再dfs求出最大层数,接着再dfs计算出最后两层的节点个数,也可以直接一遍dfs,顺便存储各个层的节点数. #include <iostream> #include <cstdio> #include <algorithm> #include <string.h> #define LEFT 1 #defin…

1115. Counting Nodes in a BST (30) 时间限制 400 ms 内存限制 65536 kB 代码长度限制 16000 B 判题程序 Standard 作者 CHEN, Yue 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 nod…

统计每层的叶子节点个数建树,然后dfs即可 #include <iostream> #include <cstdio> #include <algorithm> #include <cstring> #include <vector> using namespace std; /* 统计每层的叶子节点个数 建树,然后dfs即可 */ ; int n,m; int layer[maxn]; //统计每层的叶子节点个数 ; vector<int…

n位数,总共有0~10^n-1共计10^n个数那么所有数出现的总次数变为n*(10^n)个数1出现的次数便是十分之一,所以n位数中,1出现的次数为n*10^(n-1)知道这一个后,接下来就方便求了. 举个例子就方便理解了 3125 从头到尾for一遍 3:那么便有三组1000以内的:0~999,1000~1999,2000~29991000以内的1的个数为300,所以共有3*300=900但是又因为1000~1999中千位上的1也要算进去,有1000个所以0~2999中总共有900+1000=1…

简单题.统计一下即可. #include<cstdio> #include<cstring> #include<cmath> #include<vector> #include<map> #include<queue> #include<stack> #include<algorithm> using namespace std; +; struct Node { int left; int right; in…

题目就是给出一棵二叉搜索树,已知根节点为0,并且给出一个序列要插入到这课二叉树中,求这棵二叉树层次遍历后的序列. 用结构体建立节点,val表示该节点存储的值,left指向左孩子,right指向右孩子.中序遍历的顺序正好是序列从小到大的顺序,因此中序遍历的时候顺便赋值就可以了,最后层次遍历输出. 思路一:中序遍历的时候赋值 #include <iostream> #include <cstdio> #include <algorithm> #include <str…

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

题目:二叉排序树,统计最后两层节点个数 思路:数组格式存储,insert建树,dfs遍历 #include<cstdio> #include<iostream> #include<cstring> #include<algorithm> using namespace std; typedef long long LL; const int INF = 0x7FFFFFFF; const int maxn = 1e5 + 10; int n, cnt[max…

题意: 输入一个正整数N(<=1000),接着输入N个整数([-1000,1000]),依次插入一棵初始为空的二叉排序树.输出最底层和最底层上一层的结点个数之和,例如x+y=x+y. AAAAAccepted code: #define HAVE_STRUCT_TIMESPEC #include<bits/stdc++.h> using namespace std; typedef struct Node{ int value; int vis; int level; int visl,…

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…