I have a problem in the next code. Malloc work and in the while realloc work first but when it is called 2nd time it always fails. The code is part of the algorithm to get the prime factors of a number.

int main()
{
    int n, in, *ar, len = 0;
    scanf("%d", &n);
    ar = (int *) malloc(1 * sizeof(int));
    while(n % 2 == 0){
        ar[len] = 2;
        len++;
        ar = (int *) realloc(ar, len * sizeof(int));
        if(ar == NULL){
            printf("Error");
            return 1;
        }
        n /= 2;
    }
    return 0;
}

I tried with len initialized to 1 but i still fails. It is strange it does not fail on the first call but it fails on the 2nd. I have read other similar questions but i am a beginer and i didn`t understand. Thanks in advance!

I have a problem in the code. malloc works and in the while-loop, realloc() works for the first time and when it is called the second time it always fails. The code is part of an algorithm to get the prime factors of a number.

int main()
{
    int n, in, *ar, len = 0;
    scanf("%d", &n);
    ar = (int *) malloc(1 * sizeof(int));
    while(n % 2 == 0){
        ar[len] = 2;
        len++;
        ar = (int *) realloc(ar, len * sizeof(int));
        if(ar == NULL){
            printf("Error");
            return 1;
        }
        n /= 2;
    }
    return 0;
}

I tried with len initialized to 1 but it still fails. It is strange it does not fail on the first call but it fails on the second call. I have read other similar questions but I am a beginner and I didn`t understand. Thanks in advance!