【LeetCode】算法题66 Plus One

题目：Plus One

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

You may assume the integer do not contain any leading zero, except the number 0 itself.

The digits are stored such that the most significant digit is at the head of the list.
即：给定一个存放整数的数组（每个元素放该整数的一位，第0个元素放最高位），并给定该整数位数。
将该整数加1并返回存放结果的数组及结果整数位数。

贴代码：

/**
* Return an array of size *returnSize.
* Note: The returned array must be malloced, assume caller calls free().
*/
int* plusOne(int* digits, int digitsSize, int* returnSize) {
int* resultDigits = (int*)malloc((digitsSize) * sizeof(int));
int i = 0;
int mark = -1;
for (i = digitsSize - 1; i >= 0; i--) {
if (digits[i] != 9) {
mark = i;
break;
}
else {
resultDigits[i] = 0;
}
}
if (mark != -1) {
resultDigits[mark] = digits[mark] + 1;
for (i = 0; i < mark; i++) {
resultDigits[i] = digits[i];
}
*returnSize = digitsSize;
return resultDigits;
}
else {
*returnSize = digitsSize + 1;
resultDigits[0] = 1;
realloc(resultDigits, (*returnSize) * sizeof(int));
resultDigits[digitsSize] = 0;
return resultDigits;
}
}