Maximize Number of Subsequences in a String LeetCode solution in Java

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class Solution {
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  public long maximumSubsequenceCount(String text, String pattern) {
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    // when pattern[0] == pattern[1]
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    if (pattern.charAt(0) == pattern.charAt(1)) {
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      long freq = 1;
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      // O(N)
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      for (int i = 0; i < text.length(); i++) {
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        if (text.charAt(i) == pattern.charAt(0)) {
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          freq++;
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        }
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      }
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      // number of subsequences : choose any two characters from freq nC2
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      return (freq * (freq - 1)) / 2;
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    }
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    // choice 1
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    String text1 = pattern.charAt(0) + text;
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    int freq = 0;
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    long count1 = 0;
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    // O(N)
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    for (int i = 0; i < text1.length(); i++) {
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      if (text1.charAt(i) == pattern.charAt(0)) {
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        freq++;
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      } else if (text1.charAt(i) == pattern.charAt(1)) {
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        count1 += freq;
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      }
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    }
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    // choice 2
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    String text2 = text + pattern.charAt(1);
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    freq = 0;
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    long count2 = 0;
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    // O(N)
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    for (int i = text2.length() - 1; i >= 0; i--) {
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      if (text2.charAt(i) == pattern.charAt(1)) {
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        freq++;
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      } else if (text2.charAt(i) == pattern.charAt(0)) {
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        count2 += freq;
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      }
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    }
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    return Math.max(count1, count2);
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  }
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}