see-66. Plus One

注意进位:

 

class Solution {
public:
    vector<int> plusOne(vector<int>& digits) {
        int i=digits.size()-1,flag=0,sum;
        vector<int> res;
        vector<int> ans;
        while(i>=0)
        {
            if(i==digits.size()-1)
                sum=digits[i]+1+flag;
            else
                sum=digits[i]+flag;
            
            res.push_back(sum%10);
            flag=sum/10; //进位
            i--;
        }
        
        if(flag>0)
            res.push_back(flag);
        
        for(i=res.size()-1;i>=0;i--)
            ans.push_back(res[i]);
        
        return ans;
    }
};