leetcode - Valid Anagram

leetcode - Valid Anagram

 

Given two strings s and t, write a function to determine if t is an anagram of s.

For example,
s = "anagram", t = "nagaram", return true.
s = "rat", t = "car", return false.

Note:
You may assume the string contains only lowercase alphabets.

class Solution {
public:
    bool isAnagram(string s, string t) {
        if(s.length() != t.length()){
            return false;
        }
        map<char,int> sHash, tHash;
        string::iterator sit=s.begin(), tit=t.begin();
        while(sit!=s.end()){
            sHash[*sit]++;
            tHash[*tit]++;
            sit++;
            tit++;
        }
        map<char,int>::const_iterator sHashIt = sHash.begin();
        
        while(sHashIt != sHash.end()){
            map<char,int>::const_iterator tHashIt = tHash.find(sHashIt->first);
            if( tHashIt == tHash.end() || sHashIt->second != tHashIt->second)
            return false;
            sHashIt++;
        }
        return true;

    }
};

验证两个数是否是仅仅字母顺序不同。

利用hashtable对每个字符计数，最后比较每个相同字符的出现次数是否相同。

 

注意map的使用方法。