cours_progra/17nov/sort.py

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2022-11-24 09:48:10 +01:00
"""
Voir commentaires concernant ce module dans l'enonce de la serie de TP.
"""
import random
import umons_cpu
def python_sort(t):
t.sort()
def insertion_sort(t):
n = len(t)
for i in range(1,n):
clef = t[i]
j = i - 1
while j >= 0 and t[j] > clef:
t[j+1] = t[j]
j = j - 1
t[j+1] = clef
def selection_sort(t):
n = len(t)
for i in range(n-1):
small = i
for j in range(i+1,n):
if t[j] < t[small]:
small = j
(t[i], t[small]) = (t[small], t[i])
# permet d'avoir une interface in place, similaire aux autres tris
def merge_sort(t):
t[:] = merge_sort_functionnal(t)
def merge_sort_functionnal(t):
n = len(t)
if n > 1:
(t1, t2) = split(t)
t1 = merge_sort_functionnal(t1)
t2 = merge_sort_functionnal(t2)
return merge(t1, t2)
else:
return t
def split(t):
""" precondition: len(t) >= 2 """
mid = len(t) // 2
t1 = t[:mid]
t2 = t[mid:]
return (t1, t2)
def merge(t1, t2):
if len(t1) == 0:
return t2
elif len(t2) == 0:
return t1
elif t1[0] < t2[0]:
return [t1[0]] + merge(t1[1:], t2)
else:
return [t2[0]] + merge(t1, t2[1:])
def dicho_search(t, x):
start = 0
end = len(t) - 1
mid = start + (end - start) // 2
while (end - start > 0) and x != t[mid]:
if x < t[mid]:
end = mid - 1
else:
start = mid + 1
mid = start + (end - start) // 2
if len(t) > 0 and x == t[mid]:
return mid
else:
return None
def test(n):
t1 = list(range(n))
t2 = list(range(n,0,-1))
t3 = []
for i in range(n):
t3.append(random.randint(0,n))
print('%7d %7.2f %7.2f %7.2f %7.2f %7.2f %7.2f %7.2f %7.2f %7.2f' % (
n,
umons_cpu.cpu_time(selection_sort, t1),
umons_cpu.cpu_time(insertion_sort, t1),
umons_cpu.cpu_time(merge_sort, t1),
umons_cpu.cpu_time(selection_sort, t2),
umons_cpu.cpu_time(insertion_sort, t2),
umons_cpu.cpu_time(merge_sort, t2),
umons_cpu.cpu_time(selection_sort, t3),
umons_cpu.cpu_time(insertion_sort, t3),
umons_cpu.cpu_time(merge_sort, t3)))
if __name__ == '__main__':
print('Temps affiches en msec')
print(' n '
't1: sel '
' ins '
' mer '
't2: sel '
' ins '
' mer '
't3: sel '
' ins '
' mer')
for i in range(100, 901, 100):
test(i)