leetcode之Plus One

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()) {

digits.push_back(1);

return digits;

}

vector<int> nums(digits.rbegin(), digits.rend());

vector<int>::iterator itr = nums.begin();

int carry = 0;

int sum = carry+*itr+1;

while (itr != nums.end()) {

if (sum<10) {

*itr = sum;

carry = 0;

break;

} else {

carry = sum/10;

*itr = sum%10;

}

itr++;

sum = carry+*itr;

}

if (carry >0) {

nums.push_back(carry);

}

vector<int> res (nums.rbegin(), nums.rend());

return res;

}

};