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.
思路：
类似于普通加法，随时判断进位的情况，最后还要判断最高位也有进位。
vector<int> plusOne(vector<int>& digits) { int carry = 0; int temp = 0; for(int i = digits.size()-1;i >= 0;i--) { if(i == digits.size()-1 ) temp = digits[i] + 1 + carry; else temp = digits[i] + carry; digits[i] = temp%10; if( temp>=10) carry = 1; else carry = 0; } if(carry == 1) digits.insert(digits.begin(),1); return digits; }
原文：http://www.cnblogs.com/hellowooorld/p/6683007.html