Leetcode:66. Plus One

Description

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

没啥好说的，注意进位问题。

代码

class Solution {
public:
vector<int> plusOne(vector<int>& digits) {
int len = digits.size();
vector<int> res;
if(len == 0) return res;

int count = 0;
for(int i = len - 1; i >= 0; --i){
if(i == len - 1){
count = (digits[i] + 1) / 10;
res.push_back((digits[i] + 1) % 10);
}
else{
res.push_back((digits[i] + count) % 10);
count = (digits[i] + count) / 10;
}
}

if(count > 0)
res.push_back(count);

for(int i = 0, j = res.size() - 1; i < j; ++i, --j)
swap(res[i], res[j]);

return res;
}
};