LeetCode of the day – #66 Plus One (Easy)

Approach – BigInt

This one was pretty straight forward though it had an interesting test case post submit. I joined the array into a string, then converted that to a Number() to add 1 then result number to convert to an array of the digits. My initial solution passed all the local test cases, though I failed on the submission test cases. While console logging I noticed the end of the array was full of zeros and realized an Integer wasn’t going to cut it. I knew I needed to switch to a BigInt though I did learn that I needed to add the n to the digit being added to a BigInt. This was a fun one. Time Complexity O(N).

Here is my solution, it could be optimized though this was my accepted solution with good enough performance:

/**
 * @param {number[]} digits
 * @return {number[]}
 */
var plusOne = function(digits) {

    // Join the numbers into a single integer and add 1.

    // Using a BigInt to cover larger numbers in test cases
    // The `n` in the +1 is required to add to a BigInt to atch the type
    const incremented = BigInt(digits.join(''))+1n;
    
    // Use a map to convert the split strings back to integer
    return([...incremented + ''].map(n => + n));
};