算法系列——加1(Plus One)_plus one 算法

题目描述

题目链接:https://leetcode-cn.com/problems/plus-one/
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

这道题目要求实现加1的程序，比较简单。我们模拟这个过程即可。
从最后一位开始遍历数字，分为9和非9两种情况，如果为9，当前为时0，继续遍历过程，否则当前位加1后直接返回。

程序实现

public class Solution {
    public int[] plusOne(int[] digits) {
        int n = digits.length;
        for(int i=n-1; i>=0; i--) {
            if(digits[i] < 9) {
                digits[i]++;
                return digits;
            }
            digits[i] = 0;
        }
        int[] newNumber = new int [n+1];
        newNumber[0] = 1;

        return newNumber;
    }
}

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