Good morning! Here's our prompt for today.

Given an integer num, write a method to determine if it is a power of 3.

The method will be called as follows:

1console.log(powerOfThree(9));
2// true
3
4console.log(powerOfThree(7));
5// false

Constraints

• The given would be a non zero positive integer in the range between 1 and 2147483647
• Expected space complexity : O(logn)
• Expected time complexity : O(1)

Try to solve this here or in Interactive Mode.

How do I practice this challenge?

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  console.log('PASSED: ' + 'powerOfThree(729) should be true');

var assert = require('assert');

​

function powerOfThree(num) {

  // Fill in this method

  return num;

}

​

console.log(powerOfThree(9));

console.log(powerOfThree(7));

​

try {

  assert.equal(powerOfThree(9), true);

​

  console.log('PASSED: ' + 'powerOfThree(9) should be true');

} catch (err) {

  console.log(err);

}

​

try {

  assert.equal(powerOfThree(7), false);

​

  console.log('PASSED: ' + 'powerOfThree(7) should be false');

} catch (err) {

  console.log(err);

}

​

try {

  assert.equal(powerOfThree(729), true);

​

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Here's our guided, illustrated walk-through.

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