Given a sequence of words, check whether it forms a valid word square.

A sequence of words forms a valid word square if the kth row and column read the exact same string, where 0 ≤ k < max(numRows, numColumns).

Note:
The number of words given is at least 1 and does not exceed 500.
Word length will be at least 1 and does not exceed 500.
Each word contains only lowercase English alphabet a-z.

这题看起来简单但是其实很容易写错

本来想j 不从0开始,而是从 i+1开始检查,可以节省时间,但是一些为Null的情况会使讨论很复杂

比如

[
"abcd",
"bnrt",
"crm",
"dtz"
]
第三行检查到m就结束了,因为j<word.get(i).length(),所以第三行发现不了z的不同;第四行如果从index=4开始检查,就会漏检z的情况 综上,这种List<List<Integer>> 结构,两两比较,最好保证其中一个始终不为null,另一个为null就报错,这样可以省掉很多讨论情况
然后要保证一个始终不为null,就需要j<word.get(i).length(), 那么为了不漏检,j要从0开始
 public class Solution {
public boolean validWordSquare(List<String> words) {
if(words == null || words.size() == 0){
return true;
} for (int i=0; i<words.size(); i++) {
for (int j=0; j<words.get(i).length(); j++) {
if (words.size()<=j || words.get(j).length()<=i || words.get(i).charAt(j)!=words.get(j).charAt(i))
return false;
}
}
return true;
}
}
 

Leetcode: Valid Word Square的更多相关文章

  1. [LeetCode] Valid Word Square 验证单词平方

    Given a sequence of words, check whether it forms a valid word square. A sequence of words forms a v ...

  2. LeetCode 422. Valid Word Square

    原题链接在这里:https://leetcode.com/problems/valid-word-square/ 题目: Given a sequence of words, check whethe ...

  3. 【LeetCode】422. Valid Word Square 解题报告(C++)

    作者: 负雪明烛 id: fuxuemingzhu 个人博客:http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 拼接出每一列的字符串 日期 题目地址:https:// ...

  4. [LeetCode] Valid Word Abbreviation 验证单词缩写

    Given a non-empty string s and an abbreviation abbr, return whether the string matches with the give ...

  5. [LeetCode] Valid Perfect Square 检验完全平方数

    Given a positive integer num, write a function which returns True if num is a perfect square else Fa ...

  6. Leetcode: Valid Word Abbreviation

    Given a non-empty string s and an abbreviation abbr, return whether the string matches with the give ...

  7. LeetCode "Valid Perfect Square"

    Typical binary search.. but take care of data overflow if you are using C++ class Solution { public: ...

  8. 422. Valid Word Square

    似乎可以沿着对角线往右往下检查,也可以正常按题设检查. 我用的后者.. public class Solution { public boolean validWordSquare(List<S ...

  9. [LeetCode] 422. Valid Word Square_Easy

    Given a sequence of words, check whether it forms a valid word square. A sequence of words forms a v ...

随机推荐

  1. Codeforces Round #363 (Div. 2)

    A题 http://codeforces.com/problemset/problem/699/A 非常的水,两个相向而行,且间距最小的点,搜一遍就是答案了. #include <cstdio& ...

  2. 浏览器-05 HTML和CSS解析1

    一个浏览器内核几个主要部分,HTML/CSS解析器,网络处理,JavaScript引擎,2D/3D图形引擎,多媒体支持等; HTML 解析和 DOM 网页基本结构 一个网页(Page),每个Page都 ...

  3. 转-临界区对象TCriticalSection与TRTLCriticalSection的区别

    TRTLCriticalSection是一个结构体,在windows单元中定义: 是InitializeCriticalSection, EnterCriticalSection, LeaveCrit ...

  4. Linux下定时任务配置-crontab

    实际中经常有一些任务需要定期执行,人工操作比较麻烦,如果定时执行将会省去很多人力,还可以在一些资源占用不多的时间段执行,linux下crontab命令就实现了这一便捷的功能,实现脚本的自动化运行. 常 ...

  5. PE530 : GCD of Divisors

    \[\begin{eqnarray*}ans&=&\sum_{i=1}^nf(i)\\&=&\sum_{i=1}^n\sum_{d|i}\gcd(d,\frac{i}{ ...

  6. Mac下抓包

    Wireshark针对UNIX Like系统的GUI发行版界面采用的是X Window(1987年更改X版本到X11).Mac OS X在Mountain Lion之后放弃X11,取而代之的是开源的X ...

  7. jpa语句报 org.springframework.dao.InvalidDataAccessApiUsageException: Parameter with that position [2] did not exist; nested exception is java.lang.IllegalArgumentException: Parameter with that position

    @Query("SELECT area from Area AS area WHERE area.state=0 AND area.name like %?1% ")Area fi ...

  8. Daily Scrum02 12.09

    今天星期一,各们课程要结课了,同时也是众多大作业要提交的时间, 但是我们仍然要继续坚持! 引用拿破仑将军的一句话, 最困难之日便是离成功不远之时! Member 任务进度 下一步工作 吴文会 寻找美术 ...

  9. antlr.collections.AST.getLine()I异常

        antlr.collections.AST.getLine()I异常 Struts+hibernate+spring项目经常遇到问题 因为Struts自带的antlr-2.7.2.jar,比H ...

  10. C fgetc

    格式:int fgetc(FILE *stream); 这个函数的返回值,是返回所读取的一个字节.如果读到文件末尾或者读取出错时返回EOF. 位于stdio.h中.从流中读取字符,即从stream所指 ...