Given a non-empty array of digits representing a non-negative integer, increment 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 contains a single digit.
You may assume the integer does not contain any leading zero, except the number 0 itself.
Example
Input: 3
Output:
[
[ 1, 2, 3 ],
[ 8, 9, 4 ],
[ 7, 6, 5 ]
]
Thoughts
- 只需要考虑当需要增加一位的特殊情况应该怎么处理，其他的只要从后往前遍历array即可。
Code(JAVA)
public int[] plusOne(int[] digits) {
int carry = 1;
for(int i = digits.length-1; i >= 0; i--) {
digits[i] += 1;
carry = digits[i] / 10;
if(carry == 0)
break;
digits[i] = digits[i] % 10;
}
if(carry == 0)
return digits;
int[]newDigits = new int[digits.length+1];
newDigits[0] = 1;
for(int i = 0; i < digits.length; i++){
newDigits[i+1] = 0;
}
return newDigits;
}
