标签：style blog color strong os for
题目：
Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases.
For example,"A man, a plan, a canal: Panama" is a palindrome."race a car" is not a palindrome.
Note:
Have you consider that the string might be empty? This is a good question to ask during an interview.
For the purpose of this problem, we define empty string as valid palindrome.
说明：
1）注意两点：a、判断满足条件的字符 b、大写变小写（本题认为不区分大小写）
2）字符串为空则true
实现：
1 class Solution { 2 public: 3 bool isPalindrome(string s) { 4 if(s.empty()) return true; 5 int len=strlen(s.c_str()); 6 int i=0; 7 int j=0; 8 for (;i<len;i++) 9 { 10 if (isChar(s[i]))//去其他符合，若有大写则大写变小写 11 { 12 s[i] = tolower(s[i]);//库函数 13 s[j++]=s[i]; 14 } 15 } 16 s[j]=‘\0‘; 17 if (s[0]==‘\0‘) return true; 18 int len2=strlen(s.c_str()); 19 i=0; 20 while(i<=len2-1-i) //判断是否回文 21 { 22 if(s[i]!=s[len2-1-i]) return false; 23 i++; 24 } 25 return true; 26 } 27 private: 28 bool isChar(char t)//判断是否满足条件字符 29 { 30 if ((‘a‘ <= t&&t<=‘z‘)||(‘A‘ <= t&&t<=‘Z‘)||(‘0‘ <= t&&t<=‘9‘)) 31 { 32 return true; 33 } 34 else 35 return false; 36 } 37 };
leetcode题解：Valid Palindrome（判断回文）,布布扣,bubuko.com
leetcode题解：Valid Palindrome（判断回文）
标签：style blog color strong os for
原文地址：http://www.cnblogs.com/zhoutaotao/p/3829994.html
