betterSolution.cpp

class betterSolution {
public:
    bool isAnagram(string s, string t) {
        unordered_map <char,int> trackMap;
        if (t.size() != s.size()) {
            return false; // If lengths are not equal, impossible to be anagram
        }
        // for s, increment counts, for t decrement
        /*
           for (u_int i=0 ; i < s.size(); i++) causes a slower runtime, why?
            - Maybe conversion from u_int to int for operator[] location?
        */ 
        for (int i = 0; i < s.size(); i++) {
            trackMap[s[i]]++;
            trackMap[t[i]]--;
        }
        for (auto kvPairs: trackMap) {
            if (kvPairs.second != 0) {
                return false; // characters did not match up exactly.
            }
        }
        return true; // All counts in hashmap are zero, meaning same letters and counts in both s and t
    }
};

solution.cpp

class Solution {
public:
    bool isAnagram(string s, string t) {
        unordered_map<char,int> s_map,t_map;
        for (int i = 0; i < s.size(); i++) {
            if (s_map.count(s[i])) {
                s_map.at(s[i])++; // increment number of times weve seen this character
            }
            else {// add first instance of char to map
                s_map.insert({s[i],1});
            }
        }

        for (int i = 0; i < t.size(); i++) {
            if (t_map.count(t[i])) {
                t_map.at(t[i])++; // increment number of times weve seen this character
            }
            else {// add first instance of char to map
                t_map.insert({t[i],1});
            }
        }
        
        return t_map == s_map;
    }   
};

Valid Anagram.md

Valid Anagram 📗

Given two strings s and t, return true if the two strings are anagrams of each other, otherwise return false.

An anagram is a string that contains the exact same characters as another string, but the order of the characters can be different.

Example 1:

Input: s = "anagram", t = "nagaram"

Output: true

Example 2:

Input: s = "rat", t = "car"

Output: false

Constraints:

1 <= s.length, t.length <= 5 * 104
s and t consist of lowercase English letters.