LeetCode--Plus One

考查，最高位有进位

class Solution {
public:
    vector<int> plusOne(vector<int> &digits) {
        // IMPORTANT: Please reset any member data you declared, as
        // the same Solution instance will be reused for each test case.
        int i;
        int n=digits.size();
        if(n==0)
            return digits;
        int mod=1;
        for(i=n-1;i>=0;--i)
        {
            digits[i]+=mod;
            mod=digits[i]/10;
            digits[i]=digits[i]%10;
            
        }
        if(mod!=0)
            digits.insert(digits.begin(),mod);
        return digits;
    }
};