LeetCode-in-Go
66. Plus One
Easy
You are given a large integer represented as an integer array digits, where each digits[i] is the ith digit of the integer. The digits are ordered from most significant to least significant in left-to-right order. The large integer does not contain any leading 0’s.
Increment the large integer by one and return the resulting array of digits.
Example 1:
Input: digits = [1,2,3]
Output: [1,2,4]
Explanation:
The array represents the integer 123.
Incrementing by one gives 123 + 1 = 124.
Thus, the result should be [1,2,4].
Example 2:
Input: digits = [4,3,2,1]
Output: [4,3,2,2]
Explanation:
The array represents the integer 4321.
Incrementing by one gives 4321 + 1 = 4322.
Thus, the result should be [4,3,2,2].
Example 3:
Input: digits = [9]
Output: [1,0]
Explanation:
The array represents the integer 9.
Incrementing by one gives 9 + 1 = 10.
Thus, the result should be [1,0].
Constraints:
1 <= digits.length <= 1000 <= digits[i] <= 9digitsdoes not contain any leading0’s.
Solution
func plusOne(digits []int) []int {
num := 1
carry := 0
var sum int
for i := len(digits) - 1; i >= 0; i-- {
if i == len(digits)-1 {
sum = digits[i] + carry + num
} else {
sum = digits[i] + carry
}
carry = sum / 10
digits[i] = sum % 10
}
if carry != 0 {
ans := make([]int, len(digits)+1)
ans[0] = carry
copy(ans[1:], digits)
return ans
}
return digits
}