shell sort

 #include <iostream> template <class elem> void swap(elem a[], int p1, int p2) { elem tmp = a[p1]; a[p1] = a[p2]; a[p2] = tmp; } template <class elem> void print(elem a[], int length) { for (int i = 0; i < length; i++) std::cout << a[i] << ' '; std::cout << std::endl; } template <class elem> void insert_sort(elem a[], int length, int increment) { for (int i = increment; i < length; i += increment) for (int j = i; j >= increment; j -= increment) if (a[j] < a[j-increment]) swap(a, j, j - increment); } template <class elem> void shell_sort(elem a[], int length) { for (int i = length/2; i > 2; i/= 2) for (int j = 0; j < i; j++) insert_sort(&a[j], length - j, i); insert_sort(a, length, 1); } int main(void) { int a[] = {42, 20, 17, 13, 28, 14, 23, 15}; print(a, 8); shell_sort(a, 8); print(a, 8); system("pause"); return 0; }