[LeetCode]66. Plus One

66. Plus One

Given a non-negative number represented as an array of digits, plus one to the number.

The digits are stored such that the most significant digit is at the head of the list.

分析

一个非负整数的每位数保存在数组中，最高位在数组头部，现在需要算出这个数加1后的结果。这个从后往前遍历即可。

源码

class Solution {
public:
vector<int> plusOne(vector<int>& digits) {
int carry = 1;
int sum = 0;
for(int i = digits.size() - 1; i >= 0; i--){
sum = digits[i] + carry;
carry = sum / 10;
digits[i] = sum % 10;
}
//最后还有进位的话需要添加一位如，99+1 = 100
if(carry > 0) digits.insert(digits.begin(),carry);
return digits;
}
};