2022-06-25

66. Plus One

Description

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:

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:

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:

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].

Constraints:

• 1 <= digits.length <= 100

• 0 <= digits[i] <= 9

• digits does not contain any leading 0's.

Solution

Approach #0

func plusOne(digits []int) []int {
    digits[len(digits)-1]++
    for i := len(digits) - 1; i >= 0; i-- {
        if i > 0 {
            if digits[i] >= 10 {
                digits[i] -= 10
                digits[i-1]++
            }
        } else {
            if digits[i] >= 10 {
                digits[i] -= 10
                digits = append([]int{1}, digits...)
            }
        }
    }
    return digits
}