387. First Unique Character in a String
来源:互联网 发布:单片机温度报警器程序 编辑:程序博客网 时间:2024/06/11 13:00
387. First Unique Character in a String
Given a string, find the first non-repeatingcharacter in it and return it's index. If it doesn't exist, return -1.
Examples:
s = "leetcode"
return 0.
s = "loveleetcode",
return 2.
Note: You may assume the string contain onlylowercase letters.
题意说可以假设只有26个小写字母
这里我采用的方法是python中的dict字典,可以包含不仅是小写字母的键值,不过执行效率不怎么高。。
逻辑如下:遍历字符串S,如果没有出现在字典中,则初始化为1,否则就加1.这里统计的是出现的次数
然后再遍历S,如果对应的键值在字典中的value是1,代表只出现了一次,则返回这个k在字符串S中的索引。
最后如果不存在则返回-1
class Solution(object): deffirstUniqChar(self, s): """ :type s: str :rtype: int """ d={} fori in s: if i not in d: d[i]=1 else: d[i]=int(d[i])+1 #value +1 fork in s: if(d[k]==1): return s.index(k) return -1
另外,还可以利用从0-25对应起相应的26个字母,再通过遍历字符串计数,相关判断后返回。
另外,还可以运用HashMap
阅读全文
0 0
- 387. First Unique Character in a String
- 387.First Unique Character in a String
- 387. First Unique Character in a String
- 387. First Unique Character in a String
- 387. First Unique Character in a String
- 387. First Unique Character in a String
- 387. First Unique Character in a String
- 387. First Unique Character in a String
- 387. First Unique Character in a String
- 387. First Unique Character in a String
- 387. First Unique Character in a String
- 387. First Unique Character in a String
- 387. First Unique Character in a String
- 387. First Unique Character in a String
- 387. First Unique Character in a String
- 387. First Unique Character in a String
- 387. First Unique Character in a String
- 387. First Unique Character in a String
- Croc Champ 2012
- Noip 2015 senior ,The semi-finals,analysis (复赛题解)
- IMX6UL ARM 工控机
- 2017学习知识+学习计划
- JS如何去除指定字符串
- 387. First Unique Character in a String
- 三、Linux——Shell脚本语言
- 第六天-Java内部类
- 比较Activity与Fragment的生命周期
- Mac系统终端通过ssh连接CentOS
- 集合框架总结
- IAR 设置TAB代码格式问题
- PyMySQL 使用笔记
- Urllib库与URLError异常处理