Number of Subsequences That Satisfy the Given Sum Condition LeetCode solution in JavaScript

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const MOD = 1000000007;
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var numSubseq = function (nums, target) {
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  nums.sort((a, b) => a - b);
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  const len = nums.length;
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  const pow = new Array(len).fill(1);
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  for (let i = 1; i < len; i++) {
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    pow[i] = (pow[i - 1] * 2) % MOD;
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  }
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  let l = 0,
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    r = len - 1,
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    ans = 0;
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  while (l <= r) {
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    if (nums[l] + nums[r] > target) {
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      r--;
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      continue;
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    } else {
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      ans = (ans + pow[r - l]) % MOD;
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      l++;
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    }
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  }
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  return ans % MOD;
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};