【leetcode】989. 数组形式的整数加法

#define MAXLEN 10001
int* addToArrayForm(int* A, int ASize, int K, int* returnSize){
    int* arr=(int*)calloc(sizeof(int),MAXLEN);
    int i, pst=MAXLEN, flag=0, temp;
    for(i=ASize-1; i>=0 || K || flag; i--){
        temp = (i>=0)?A[i] :0;
        arr[--pst]=(temp+K%10+flag)%10;
        flag=(temp+K%10+flag >= 10)?1 :0; 
        K/=10;
    }
    *returnSize=MAXLEN-pst;
    return arr+pst;
}