algorithms
Review sort, and learn Coursera lessons, share my code, and mark how to make the algorithms visually.
sorted methods
Bubble Sort
The best occasion will be o(n), one time recurse, n-1 comparision times.Bubble sort’s worst-case and average are both o(n^2)
do{
boolean unordered=false;
for(int i=0;i<array_length-1;i++)
if(left_element>right_element){
swap(left_element,right_element);
unordered=true;
}
}while(unordered==true)
Select sort
o(n^2)
for index in range(list_length-1):
smallest=index
for comparision in range(list_length-index-1):
if list[smallest]>comparison:
smallest=comparision
swap(list[index],list[comparision])
insertion sort:
def insertion_sort(list):
for index in range(1,len(list)):
j=index
while(j>0)&&list[j]<list[j-1]:
list[j],list[j-1]=list[j-1],list[j]
j-=1
return list
merge sort:
from sarath joseph
def merge_sort(x):
if len(x) < 2:return x
result,mid = [],int(len(x)/2)
y = merge_sort(x[:mid])
z = merge_sort(x[mid:])
while (len(y) > 0) and (len(z) > 0):
if y[0] > z[0]:result.append(z.pop(0))
else:result.append(y.pop(0))
result.extend(y+z)
return result
quick sort
def quick_sort(list):
result=[]
for i in range(len(list)-1):
if list[i:]<list[i]:
resutlt.append(list
calculate time
test_list = (random.sample(range(100), 50))
print(test_list)
time=bestof(merge_sort,test_list)
print(time)
use the same list, test each time consuming:
[7, 84, 89, 47, 73, 24, 91, 55, 70, 44, 23, 80, 3, 25, 94, 58, 64, 17, 76, 12, 6, 87, 42, 51, 75, 20, 30, 22, 74, 41, 61, 52, 53, 1, 27, 56, 38, 79, 83, 93, 4, 86, 90, 69, 0, 96, 46, 40, 67, 50]
0.00018517441462646942 merge sort
1.3257290654551017e-05 insert sort
0.00017491070573262373 select sort
1.1119017968332957e-05 Bubble sort
