题目:
Given a non-empty array of digits representing a non-negative integer, plus one to the integer.
The digits are stored such that the most significant digit is at the head of the list, and each element in the array contain a single digit.
You may assume the integer does not contain any leading zero, except the number 0 itself.
Example 1:
Input: [1,2,3] Output: [1,2,4] Explanation: The array represents the integer 123.
Example 2:
Input: [4,3,2,1] Output: [4,3,2,2] Explanation: The array represents the integer 4321.
描述:
给出一个数组,表示一个数,输出该数+1后对应的数组
分析:
模拟大数加法...
关键就是进位检查
代码:(时间复杂度O(n),空间复杂度O(1))
class Solution {
public:
vector<int> plusOne(vector<int>& digits) {
int len = digits.size(), index = len - 1;
int carry = 1;
while (carry && index >= 0) {
digits[index] += carry;
carry = digits[index] / 10;
digits[index] %=10;
-- index;
}
if (carry) {
digits.insert(digits.begin(), 1);
}
return digits;
}
};