leetcode—Plus one

[code]Given a number represented as an array of digits, plus one to the number.

[code]class Solution {

public:

vector<int> plusOne(vector<int> &digits) {

// Start typing your C/C++ solution below

// DO NOT write int main() function

if(digits.empty())return digits;

int len=digits.size();

int i=len-1;

while(i>=0)

{

    if(digits[i]==9)digits[i]=0;

    else{

digits[i]+=1;break;

}

    i--;

}

if(i<0)digits.insert(digits.begin(),1);

return digits;

}

};