LeetCode 算法题【Easy】：66. Plus One

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链接：https://leetcode.com/problems/plus-one/

Question

You are given a large integer represented as an integer array digits, where each digits[i] is the ith digit of the integer. The digits are ordered from most significant to least significant in left-to-right order. The large integer does not contain any leading 0‘s.

Increment the large integer by one and return the resulting array of digits.

Example 1:

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Input: digits = [1,2,3]
Output: [1,2,4]
Explanation: The array represents the integer 123.
Incrementing by one gives 123 + 1 = 124.
Thus, the result should be [1,2,4].

Example 2:

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Input: digits = [4,3,2,1]
Output: [4,3,2,2]
Explanation: The array represents the integer 4321.
Incrementing by one gives 4321 + 1 = 4322.
Thus, the result should be [4,3,2,2].

Example 3:

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Input: digits = [9]
Output: [1,0]
Explanation: The array represents the integer 9.
Incrementing by one gives 9 + 1 = 10.
Thus, the result should be [1,0].

My Answer

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var plusOne = function(digits) {
    const digitsLen = digits.length
    const lastDigit = digits[digitsLen - 1]
    if (lastDigit !== 9) return [...digits.slice(0, digitsLen - 1), lastDigit + 1]
    let index = digitsLen - 1
    do {
      index --
    } while(digits[index] === 9)
    const prefix = index < 0 ? [] : digits.slice(0, index)
    const addedNum = index >= 0 ? digits[index] + 1 : 1
    return prefix.concat(addedNum).concat(new Array(digitsLen - index - 1).fill(0))
};

My Answer’s Performance

3