Count Number of Teams LeetCode solution in Java

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// Smaller * Larger Solution
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// sum of #smaller * #larger
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// Time complexity: O(N^2)
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// Space complexity: O(1)
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class Solution {
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  public int numTeams(int[] rating) {
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    final int N = rating.length;
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    int res = 0;
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    for (int i = 1; i < N; i++) {
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      res += smaller(rating, i, -1) * larger(rating, i, 1);
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      res += larger(rating, i, -1) * smaller(rating, i, 1);
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    }
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    return res;
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  }
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  private int smaller(int[] rating, int i, int diff) {
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    int t = rating[i], count = 0;
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    i += diff;
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    while (i >= 0 && i < rating.length) {
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      if (rating[i] < t) count++;
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      i += diff;
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    }
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    return count;
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  }
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  private int larger(int[] rating, int i, int diff) {
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    int t = rating[i], count = 0;
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    i += diff;
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    while (i >= 0 && i < rating.length) {
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      if (rating[i] > t) count++;
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      i += diff;
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    }
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    return count;
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  }
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}