c++ - Dealloc core dump -

i have problem implementation of counting sort.

i have traced error delete [] c gives me core dump during execution. if remove delete program works normally. what's reason of this? can't explain caused by. post below main , counting_sort functions. there other functions create random numbers , stamp.

void counting_sort (int *a, int n, int k) {     int *b = new int [k];      //array b's inizialization     (int i=0; i<k; i++)        b[i] = 0;     //presence counter in array "a"     (int i=0; i<n; i++)        b[a[i]]++;     //b's element sum    (int i=0; i<k-1; i++)        b[i+1] += b[i];      int *c = new int [n];     //final sort    (int i=0; i<n; i++)    {       c[b[a[i]]] = a[i];       b[a[i]]--;    }     delete [] b;     //coping c's elements    (int i=0; i<n; i++)       a[i] = c[i];   **delete [] c**; }     int main() {    cout<<"type array size: ";    int n;    cin>>n;    int *a = new int [n];     cout<<"type maximum value array contain: ";    int k;    cin>>k;     random_n(a,n,k);    stamp(a,n);     counting_sort(a,n,k+1);    stamp(a,n);    delete [] a;      return 0; }