[Algorithm] Universal Value Tree Problem
A unival tree (which stands for "universal value") is a tree where all nodes under it have the same value.
Given the root to a binary tree, count the number of unival subtrees.
For example, the following tree has 5 unival subtrees:
0
/ \
1 0
/ \
1 0
/ \
1 1
function Node(val) {
return {
val,
left: null,
right: null
};
} const root = Node();
root.left = Node();
root.right = Node();
root.right.left = Node();
root.right.right = Node();
root.right.left.left = Node();
root.right.left.right = Node(); function count_unival(root) {
function helper(root) {
let total_count = ;
let is_unival = true; // Base case 1: if current node is null, then return
if (root == null) {
return [, true];
} // Base case 2: if current node is not null, but its children node
// are null, then count this node as usb-unvial tree
if (root.left === null && root.right === null) {
return [, true];
} // Base case 1 & Base case 2 can keep just one, it should still works // Do the Recursion
let [left_count, is_left_unival] = helper(root.left);
let [right_count, is_right_unival] = helper(root.right); // we need to consider whether the whole tree
// root + left tree + right tree are unvial
// the way to do it just compare root with its left and right node
// whether they are the same if both left tree and right tree are
// unival tree.
if (!is_left_unival || !is_right_unival) {
is_unival = false;
} if (root.left !== null && root.val !== root.left.val) {
is_unival = false;
} if (root.right !== null && root.val !== root.right.val) {
is_unival = false;
} // If the whole tree are unival tree, then the final result
// should + 1
if (is_unival) {
return [left_count + right_count + , is_unival];
} else {
return [left_count + right_count, is_unival];
}
} const [total_count, is_unival] = helper(root);
return [total_count, is_unival];
} const res = count_unival(root);
console.log(
`Whole tree is${
res[] ? "" : "n't"
} unival tree, total counts for sub-unival tree is ${res[]}`
); // Whole tree isn't unival tree, total count is 5
[Algorithm] Universal Value Tree Problem的更多相关文章
- BNU 28887——A Simple Tree Problem——————【将多子树转化成线段树+区间更新】
A Simple Tree Problem Time Limit: 3000ms Memory Limit: 65536KB This problem will be judged on ZJU. O ...
- xtu数据结构 I. A Simple Tree Problem
I. A Simple Tree Problem Time Limit: 3000ms Memory Limit: 65536KB 64-bit integer IO format: %lld ...
- ZOJ 3686 A Simple Tree Problem
A Simple Tree Problem Time Limit: 3 Seconds Memory Limit: 65536 KB Given a rooted tree, each no ...
- 2014 Super Training #9 F A Simple Tree Problem --DFS+线段树
原题: ZOJ 3686 http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemCode=3686 这题本来是一个比较水的线段树,结果一个ma ...
- ZOJ-3686 A Simple Tree Problem 线段树
题目链接:http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemCode=3686 题意:给定一颗有根树,每个节点有0和1两种值.有两种操作: ...
- Teemo's tree problem
题目链接 : https://nanti.jisuanke.com/t/29228 There is an apple tree in Teemo's yard. It contains n node ...
- ZOJ 3686 A Simple Tree Problem(线段树)
Description Given a rooted tree, each node has a boolean (0 or 1) labeled on it. Initially, all the ...
- [Algorithm] 1. A+B Problem
Description Write a function that add two numbers A and B. Clarification Are a and b both 32-bit int ...
- [Algorithm] 94. Binary Tree Inorder Traversal iteratively approach
Given a binary tree, return the inorder traversal of its nodes' values. Example: Input: [1,null,2,3] ...
随机推荐
- WinForm 使用 NPOI 2.2.1从datatable导出Excel
最新的NOPI应该是2.3了,但在官网上还是2.2.1. 也是第一次使用NPOI来导出Excel文件. 在写的时候搜不到2.2.1的教程,搜了一个2.2.0的教程. 不过也没什么问题,NPOI是真的方 ...
- ZeptoLab Code Rush 2015 B. Om Nom and Dark Park DFS
B. Om Nom and Dark Park Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/5 ...
- Codeforces Round #279 (Div. 2) B - Queue 水题
#include<iostream> #include<mem.h> using namespace std; ],q[]; int main() { int n,x,y; m ...
- Android 通话记录分析
http://stackoverflow.com/questions/6786666/how-do-i-access-call-log-for-android http://android2011de ...
- 3.3V与5V电平双向转换
http://www.amobbs.com/thread-5541344-1-2.html 3.3V转5V:S3输入为0V时,NMOS管导通,S5=S3=0V:S3输入为3.3V时,NMOS管截止,S ...
- IT程序猿们,我该做什么选择呢
这个时刻,我想我遇到人生小拐点了,程序猿到了30岁,到达了一个分界线了,现在的我该何去何从呢? 先谈下简单的情况吧: 来这个公司2年了,之前因为身体的原因,不想那么累,于是选择了一份维护的工作,就来了 ...
- iOS中bundle的意义
什么是bundle? bundle就是一个文件夹,按照一定标准组织的目录结构.每个iOS APP至少有一个main bundle,这个main bundle包含了app的二进制代码及任何你用到的资源, ...
- 给.DLL文件加一个数字签名的方法
给.dll文件加一个数字签名的方法 效果如图所示: 做法: 下载数字签名工具包:http://files.cnblogs.com/babyt/SignTool.rar /Files/JavaC ...
- Remon Spekreijse CSerialPort串口类的修正版2014-01-10
转自:http://m.blog.csdn.net/blog/itas109/18358297# 2014-1-16阅读691 评论0 如需转载请标明出处:http://blog.csdn.net/i ...
- Oracle 快速插入1000万条数据的实现方式
1.使用dual配合connect by level create table BigTable as select rownum as id from dual connect by level & ...