7.7.23(2024. Maximize the Confusion of an Exam(Medium))

class Solution {

    int find_maxlength(string &answerKey,int k,int ch)
    {
        int ans = 0;
        vector<int>index;
        int ind = 0;
        int i = 0, j = 0;
        while(j < answerKey.size())
        {
            if(answerKey[j] == ch)
            {
                index.push_back(j);
                k--;
            }
            if(k < 0)
            {
                ans = max(ans,j-i);
                i = index[ind++]+1;
                k++;
            } 
            j++;
        }
        ans = max(ans,j-i);
        return ans;
    }
public:
    int maxConsecutiveAnswers(string answerKey, int k) 
    {
       // we allow only k flips inside a window

        int ans = max(find_maxlength(answerKey,k,'F'),find_maxlength(answerKey,k,'T'));
        return ans;
    }
};