【leetcode】加一

int* plusOne(int* digits, int digitsSize, int* returnSize){
    int i,carry=1;
    int* arr = (int*)calloc(digitsSize+1,sizeof(int));
    for (i=digitsSize-1; i>=0; i--)
    {
        if (digits[i] + carry < 10) 
        {
            arr[i+1] = digits[i] + carry;
            carry=0;
        }
        else arr[i+1] = 0;
    }
    *returnSize = digitsSize + carry;
    arr[0] = 1;
    return (carry)? arr : arr+1;
}