Check if There is a Valid Partition For The Array LeetCode solution in JavaScript

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var validPartition = function (nums) {
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  let n = nums.length,
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    memo = Array(n).fill(-1);
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  return dp(0);
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  function dp(i) {
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    if (i === n) return true;
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    if (i === n - 1) return false;
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    if (memo[i] !== -1) return memo[i];
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    if (nums[i] === nums[i + 1] && dp(i + 2)) return (memo[i] = true);
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    if (i < n - 2) {
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      if (!dp(i + 3)) return (memo[i] = false);
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      let hasThreeEqual =
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        nums[i] === nums[i + 1] && nums[i + 1] === nums[i + 2];
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      let hasThreeConsecutive =
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        nums[i] + 1 === nums[i + 1] && nums[i + 1] + 1 === nums[i + 2];
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      if (hasThreeEqual || hasThreeConsecutive) return (memo[i] = true);
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    }
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    return (memo[i] = false);
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  }
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};