Longest Substring with Same Letters after Replacement

gistfile1.txt

import java.util.*;

class StringPermutation {
  // obdbcaf
  public static boolean findPermutation(String str, String pattern) {
    int left = 0;
    int patternLength = pattern.length();
    HashMap<Character, Integer> map = new HashMap();

    for(int i = 0; i < pattern.length(); i++){
      int count = map.getOrDefault(pattern.charAt(i), 0) + 1;
      map.put(pattern.charAt(i), count);
    }


    for(int right = 0; right < str.length(); right++){

      char c = str.charAt(right);

      if(map.containsKey(c)) {
        int desc = map.getOrDefault(c, 0) -1;
        map.put(c, desc);
        patternLength--;
        if(patternLength == 0) return true;
      } else {
        if(patternLength == 0) return true;
        while(left < right) {
          char previousC = str.charAt(left);
        if(map.containsKey(previousC)) {
            int inc = map.getOrDefault(previousC, 0) +1;
            map.put(previousC, inc);
            patternLength++;
        }
        left++;
        }
      }
    }
    return false;
  }
}