[leetcode] 66. Plus One 解题报告

Posted 2020-10-08

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.

从后往前遍历只对小于9的数字进行+1处理后返回即可，如第一位仍为9，新建数组

public int[] plusOne(int[] digits) {
        int n = digits.length;
        //一般情况
        for (int i = n - 1; i >= 0; i--){
            if (digits[i] < 9){
                digits[i]++;
                return digits;
            } else {
                digits[i] = 0;
            }
        }
        //9999--》10000
        int[] newNumber = new int[n + 1];
        newNumber[0] = 1;
        return newNumber;
    }