Java for LeetCode 038 Count and Say
The count-and-say sequence is the sequence of integers beginning as follows:
1, 11, 21, 1211, 111221, ...
1
is read off as "one 1"
or 11
.
11
is read off as "two 1s"
or 21
.
21
is read off as "one 2
, then one 1"
or 1211
.
Given an integer n, generate the nth sequence.
Note: The sequence of integers will be represented as a string.
解题思路:
题目的理解很关键,n=1时返回“1”,n=2时返回“11”,n=3时返回"21",n=4时返回"1211"
所以肯定是用递归也进行求解,JAVA实现如下:
static public String countAndSay(int n) {
if(n==1)
return "1";
return countAndSay(countAndSay(n-1));
} static String countAndSay(String s){
StringBuilder sb = new StringBuilder();
int count = 0;
char temp='*';
for(int i=0;i<s.length();i++){
if(temp!=s.charAt(i)){
if(temp!='*'){
sb.append(count);
sb.append(temp);
}
count=1;
temp=s.charAt(i);
}
else
count++;
}
sb.append(count);
sb.append(temp);
return sb.toString();
}
Java for LeetCode 038 Count and Say的更多相关文章
- [LeetCode] 038. Count and Say (Easy) (C++/Python)
索引:[LeetCode] Leetcode 题解索引 (C++/Java/Python/Sql) Github: https://github.com/illuz/leetcode 038. Cou ...
- Java for LeetCode 222 Count Complete Tree Nodes
Given a complete binary tree, count the number of nodes. Definition of a complete binary tree from W ...
- Java for LeetCode 204 Count Primes
Description: Count the number of prime numbers less than a non-negative number, n. 解题思路: 空间换时间,开一个空间 ...
- LeetCode 038 Count and Say
题目要求:Count and Say The count-and-say sequence is the sequence of integers beginning as follows:1, 11 ...
- Java for LeetCode 210 Course Schedule II
There are a total of n courses you have to take, labeled from 0 to n - 1. Some courses may have prer ...
- Java for LeetCode 200 Number of Islands
Given a 2d grid map of '1's (land) and '0's (water), count the number of islands. An island is surro ...
- Java for LeetCode 216 Combination Sum III
Find all possible combinations of k numbers that add up to a number n, given that only numbers from ...
- Java for LeetCode 214 Shortest Palindrome
Given a string S, you are allowed to convert it to a palindrome by adding characters in front of it. ...
- Java for LeetCode 212 Word Search II
Given a 2D board and a list of words from the dictionary, find all words in the board. Each word mus ...
随机推荐
- jQuery Select的操作集合
1. $("#select_id").change(function(){... }); //为select添加事件,当选择其中一项时触发2. $("#select_ ...
- 【HDU 2955】Robberies(DP)
题意是给你抢劫每个银行可获得的钱m和被抓的概率p,求被抓的概率小于P,最多能抢多少钱.01背包问题,体积是m,价值是p.被抓的概率不是简单相加,而应该是1−Π(1−p[i])DP:dp[i]表示抢到i ...
- 【POJ 1035】Spell checker
题 题意 每个单词,如果字典里存在,输出”该单词 is correct“:如果字典里不存在,但是可以通过删除.添加.替换一个字母得到字典里存在的单词,那就输出“该单词:修正的单词”,并按字典里的顺序输 ...
- poj 3233 矩阵快速幂+YY
题意:给你矩阵A,求S=A+A^1+A^2+...+A^n sol:直接把每一项解出来显然是不行的,也没必要. 我们可以YY一个矩阵: 其中1表示单位矩阵 然后容易得到: 可以看出这个分块矩阵的左下角 ...
- Linux内核之内存管理完全剖析
linux虚拟内存管理功能 ? 大地址空间:? 进程保护:? 内存映射:? 公平的物理内存分配:? 共享虚拟内存.实现结构剖析 (1)内存映射模块(mmap):负责把磁盘文件的逻辑地址映射到虚拟地 ...
- <jsp:invoke fragment=""/>的理解和使用
在传统 JSP 中,想要实现页面布局管理比较麻烦,为了解决在 JSP 中布局的问题,出现了很多开源软件,比如 Apache Tiles 和 SiteMesh 就是其中比较优秀的.但是使用开源软件实现布 ...
- What to call your Academic Event
- hdu 2187 悼念512汶川大地震遇难同胞——老人是真饿了
题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=2187 题目简问: 解题思路: 已知给出了 总钱数 和 一共的种类 1. 对给出的大米,按照价格进行升序 ...
- 解决:[INS-20802] Oracle Net Configuration Assistant failed
在linux 中安装Oracle 11G 的时辰呈现 [INS-20802] Oracle Net Configuration Assistant failed 是oracle数据库的鼓掌,须要补丁p ...
- 新浪微博客户端(18)-集成下拉刷新控件UIRefreshControl
HomeViewController.m - (void)setupPullToRefreshView { UIRefreshControl *refreshControl = [[UIRefresh ...