leetcode 66---Plus One 進位 數組

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

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

解題思路：整數加1，需要考慮的是進位和最後的結果會不會多一位，比如99，999這樣的情況。

package leedcode;public class plusOne {    private static int[] plus(int[] digits) {        if(digits.length==0||digits==null) return digits;        for (int i = digits.length - 1; i >= 0; i--) { //迴圈本質上代替了進位            digits[i] = digits[i] + 1;            if (digits[i] == 10)                digits[i] = 0;            else                return digits;        }        int[] res= new int[digits.length + 1];        res[0] = 1;        return res;    }    public static void main(String[] args) {        int[] tes = { 9, 9 };        int[] res = plus(tes);        for (int i = 0; i < res.length; i++) {            System.out.print(res[i] + " ");        }    }}