Knight Dialer LeetCode solution in Java

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class Solution {
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  public int knightDialer(int n) {
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    var dp = new long[10];
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    var tmp = new long[10];
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    Arrays.fill(dp, 1);
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    for (int i = 1; i < n; i++) {
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      tmp[1] = dp[6] + dp[8];
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      tmp[2] = dp[7] + dp[9];
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      tmp[3] = dp[4] + dp[8];
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      tmp[4] = dp[0] + dp[3] + dp[9];
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      tmp[5] = 0;
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      tmp[6] = dp[0] + dp[1] + dp[7];
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      tmp[7] = dp[2] + dp[6];
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      tmp[8] = dp[1] + dp[3];
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      tmp[9] = dp[2] + dp[4];
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      tmp[0] = dp[4] + dp[6];
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      for (int j = 0; j < 10; j++) tmp[j] = tmp[j] % 1000000007;
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      var arr = dp;
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      dp = tmp;
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      tmp = arr;
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    }
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    long res = 0;
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    for (int i = 0; i < 10; i++) {
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      res = (res + dp[i]) % 1000000007;
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    }
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    return (int) res;
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  }
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}