isAnagram.cpp

/*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.
Follow up:
What if the inputs contain unicode characters? How would you adapt your solution to such case?
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//my Solution 
#include<map>
class Solution {
public:
    bool isAnagram(string s, string t) {
        if(s.length()!=t.length())
            return false;
        map<char,int> sci;
        for(auto c:s)
            if(sci.find(c)==sci.end())
                sci[c]=1;
            else
                sci[c]++;
        for(auto c:t)
        {
            if(sci.find(c)!=sci.end())
            {
                if(sci[c]>1)
                    sci[c]--;    
                else
                    sci.erase(c);
            }else
            return false;
        }
        return true;
    }
};




//better Solution 
class Solution {
public:
    bool isAnagram(string s, string t) {
        if (s.length() != t.length()) return false;
        int n = s.length();
        unordered_map<char, int> counts;
        for (int i = 0; i < n; i++) {
            counts[s[i]]++;
            counts[t[i]]--;
        }
        for (auto count : counts)
            if (count.second) return false;
        return true;
    }
};

//better Solution 
class Solution {
public:
    bool isAnagram(string s, string t) {
        if (s.length() != t.length()) return false;
        int n = s.length();
        int counts[26] = {0};
        for (int i = 0; i < n; i++) { 
            counts[s[i] - 'a']++;
            counts[t[i] - 'a']--;
        }
        for (int i = 0; i < 26; i++)
            if (counts[i]) return false;
        return true;
    }
};