题目

Given a non-negative integer represented as a non-empty array of digits, plus one to the integer.

You may assume the integer do not contain any leading zero, except the number 0 itself.

The digits are stored such that the most significant digit is at the head of the list.

解题思路

用一个0-9的数字组成的数组代表一个正整数，将这个正整数加1
个位加1后，需要从个位开始逆序遍历这个数组，更新每一位的值，注意进位

代码

func plusOne(digits []int) []int {
    len1 := len(digits)

    digits[len1 - 1] = digits[len1 - 1] + 1
    var carry int
    if digits[len1 - 1] == 10 {
        carry = 1
        digits[len1 - 1] = 0
    }


    for i := len1-2; i >= 0; i-- {
        digits[i] = carry + digits[i]
        if digits[i] == 10 {
            digits[i] = 0
            carry = 1
        } else {
            carry = 0
        }
    }

    if carry == 1 {
        var ret []int
        ret = append([]int{carry}, digits...)
        return ret
    } else {
        return digits
    }
}