3223. Minimum Length of String After Operations

Hint

class Solution {
public:
    int minimumLength(string s)
    {
        // Initialize n to the size of the input string s
        // Initialize a frequency vector for the 26 lowercase English letters

        // Iterate over each character in the string
        for ()
        {
            // Increment the frequency count for the current character
            // If the frequency of the current character reaches 3
                // Reduce the frequency count by 2 (essentially removing 2 instances)
                // Decrease the length of the string by 2
        }
        // Return the adjusted length of the string
    }
};

class Solution {
public:
    int minimumLength(string s)
    {
        int n = s.size();
        vector<int> freq(26);
        for (char c : s)
        {
            ++freq[c - 'a'];
            if (freq[c - 'a'] == 3)
            {
                freq[c - 'a'] -= 2;
                n -= 2;
            }
        }
        return n;
    }
};

• T: $O(n)$
• S: $O(1)$