LeetCode - Plus One - Frequent

https://leetcode.com/problems/plus-one/

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.
这道题蛮简单的，就是最后一位先加1，如果有carry就往前加知道没有carry为止，如果加到最后还有carry，就需要一个新数组，因为新数的位数为原来位数大了。
代码如下：

public int[] plusOne(int[] digits) {
int num = digits[digits.length-1]+1;
digits[digits.length-1] = num%10;
int carry = num/10;
int i=digits.length-2;
while(carry!=0 && i>=0){
num = digits[i]+carry;
digits[i]=num%10;
carry = num/10;
i--;
}
if(carry==0) return digits;
else{
int[] rst = new int[digits.length+1];
rst[0] = carry;
for(i=0; i<digits.length; i++){
rst[i+1] = digits[i];
}
return rst;
}
}