add sort
delete old files
modifed sort
finish permute algorithm with merge sort
add permution algorithm by random in place
unfinished heap sort
add priority queue
add finished heap sort and quick sort
add randomized quick sort and fix a bug in previous quick sort

when we sort two partitioned array, we should not include the pivot, which
would cause a fault. say start is 5 and end is 6, we choose 6 as pivot and if
the array is sorted, we would jump into an infinite call loop of quick sort
add counting sort
add radix merge sort
Unfinished bucket sort
add bucket sort with using insertion sort to sort subarray

why not try radix sort with counting sort sorting each digit?