Simple insertion sort

insertion.c

void insertion_sort(int *arr, int len) {
	int p;
	for (p=1; p<len; p++) {
		int n = arr[p], p2 = p;
		while (p2 > 0 && n < arr[p2-1])
			arr[p2] = arr[--p2];
		arr[p2] = n;
	}
}