Leet -- Plus One
题目描述：
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.
当前位= num[i]%10
进位= num[i]/10
实现代码：
public class Solution {
public int[] PlusOne(int[] digits) {
if (digits == null || digits.Length == 0){
return null;
}
var len = digits.Length;
var c = digits[len-1] == 9 ? 1: 0;
digits[len-1] = digits[len-1] == 9 ? 0 : digits[len-1] + 1;
for(var i = len - 2;i >= 0 ; i--){
var s = digits[i] + c ;
c = s / 10;
digits[i] = s % 10;
}
if(c > 0){
var arr = new List<int>{1};
arr.AddRange(digits);
return arr.ToArray();
}
return digits;
}
}