Intervals Between Identical Elements LeetCode solution in Java

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class Solution {
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  public long[] getDistances(int[] arr) {
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    long[] output = new long[arr.length];
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    Map<Integer, Long> sumMap = new HashMap<>();
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    Map<Integer, Integer> countMap = new HashMap<>();
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    for (int i = 0; i < arr.length; ++i) {
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      if (!sumMap.containsKey(arr[i])) {
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        sumMap.put(arr[i], 0l);
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        countMap.put(arr[i], 0);
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      }
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      output[i] += i * (long) countMap.get(arr[i]) - sumMap.get(arr[i]);
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      sumMap.put(arr[i], sumMap.get(arr[i]) + i);
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      countMap.put(arr[i], countMap.get(arr[i]) + 1);
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    }
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    sumMap = new HashMap<>();
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    countMap = new HashMap<>();
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    int len = arr.length;
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    for (int i = len - 1; i >= 0; --i) {
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      if (!sumMap.containsKey(arr[i])) {
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        sumMap.put(arr[i], 0l);
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        countMap.put(arr[i], 0);
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      }
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      output[i] += (len - i - 1) * (long) countMap.get(arr[i]) - sumMap.get(arr[i]);
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      sumMap.put(arr[i], sumMap.get(arr[i]) + (len - i - 1));
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      countMap.put(arr[i], countMap.get(arr[i]) + 1);
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    }
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    return output;
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  }
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}