Construct String With Repeat Limit LeetCode solution in Java

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class Solution {
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  public String repeatLimitedString(String s, int repeatLimit) {
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    int[] counter = new int[26];
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    int max = 0;
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    for (char ch : s.toCharArray()) {
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      int curr = ch - 'a';
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      max = Math.max(max, curr);
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      counter[curr]++;
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    }
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    int repeated = 0;
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    StringBuilder builder = new StringBuilder();
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    while (max >= 0) {
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      builder.append((char) ('a' + max));
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      counter[max]--;
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      repeated++;
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      if (counter[max] == 0) {
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        max = findNextMax(counter, max - 1);
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        repeated = 0;
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        continue;
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      }
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      if (repeated == repeatLimit) {
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        // Greedy, use the next possible char once and get back to curr.
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        // if no other char available, the curr word is the largest subsequence.
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        int lower = findNextMax(counter, max - 1);
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        if (lower < 0) {
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          return builder.toString();
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        }
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        builder.append((char) ('a' + lower));
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        counter[lower]--;
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        repeated = 0;
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      }
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    }
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    return builder.toString();
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  }
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  private int findNextMax(int[] counter, int from) {
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    int curr = from;
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    while (curr >= 0) {
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      if (counter[curr] > 0) {
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        return curr;
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      }
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      curr--;
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    }
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    return curr;
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  }
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}