1898

class Solution {
public:
    int maximumRemovals(string s, string p, vector<int>& removable) {
        int n = removable.size();
        int left = 0, right=n, ans = 0;
        vector<int> masked(s.size()+1);
        while(left<=right){
            int mid = (left+right)/2;
            for(int i=0; i<s.length(); i++){
                masked[i] = 0;
            }
            for(int i=0; i<mid; i++)
                masked[removable[i]] = 1;

            if(check(p, s, masked)){
                ans = mid;
                left = mid+1;
            }
            else{
                right = mid-1;
            }
        }
        return ans;
    }

    bool check(string t, string s, vector<int> &masked) {
      int n = s.size();
      int m = t.size();
      int j = 0;
      for(int i = 0; i < n; i++){
         if(masked[i]) continue;
         if(t[j] == s[i])
         j++;
         if(j == t.size())
         return true;
      }
      return false;
   }

};