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Devoirs :
(Sujet)
## 1 Somme
def est_valide(ch):
if ch[0] == '+' or ch[-1]=='+':
return False
n = len(ch)
for i in range(n):
if ch[i]=='+':
if ch[i+1]=='+':
return False
else:
if not ch[i].isdigit():
return False
return True
## 2 Evaluation
def evalue(ch):
l = ch.split('+')
s = 0
for x in l:
s = s+int(x)
return s
## 3 Liste d'additions
def plus_grande_somme(l):
ll = [evalue(x) for x in l]
return max(ll)
## 4 Expressions arithmétiques
def calcule(a,b,op):
if op == '+':
return a+b
if op == '-':
return a-b
if op == '*':
return a*b
if op == '/':
return a//b
## 5 Evaluation
def evaluation(l):
if len(l)==1: return l[0]
else:
a,op,b = l.pop(0), l.pop(0), l.pop(0)
l = [calcule(a,b,op)] + l
return evaluation(l)
def evaluation2(l):
r=l[0]
n = len(l)
i=1
while i<n:
r = calcule(r,l[i+1],l[i])
i=i+2
return r
## 6 Expression postfixee
def postfix(l):
ope = ['+','-','*','/']
pile = []
for x in l:
if x in ope:
b,a = pile.pop(),pile.pop()
pile.append(calcule(a,b,x))
else:
pile.append(x)
return pile[0]
## 7 Verification d'erreur
def postfix(l):
ope = ['+','-','*','/']
pile = []
for x in l:
if x in ope:
if len(pile) <2: return 'ERR'
b,a = pile.pop(),pile.pop()
if x=='/' and b==0: return 'ERR'
pile.append(calcule(a,b,x))
else:
pile.append(x)
if len(pile)!=1: return 'ERR'
return pile[0]
(Sujet)
## Tri par Insertion
def triInsertion(l):
ll = l[:]
n = len(ll)
for i in range(n):
element = ll[i]
j = i
while (j>0 and ll[j-1] > element):
ll[j] = ll[j-1]
j = j-1
ll[j] = element
return ll
def triInsertionMieux(l):
ll = l[:]
n = len(ll)
for i in range(n):
element = ll[i]
j = i
while (j>0 and ll[j-1] > element):
j = j-1
ll.insert(j,element)
del(ll[i+1])
return ll
## Tri fusion
def divise(l):
n=len(l)
return l[:n//2],l[n//2:]
def fusion(l1,l2):
if l1 == []: return l2
if l2 == []: return l1
if l1[0] <= l2[0]:
return [l1[0]] + fusion(l1[1:],l2)
else:
return [l2[0]] + fusion(l1,l2[1:])
def fusion(l1,l2):
l = []
while (l1!=[] and l2!=[]):
if l1[0] > l2[0]:
l.append(l2[0])
del(l2[0])
else:
l.append(l1[0])
del(l1[0])
if l1==[]:
return l + l2
else:
return l+l1
def triFusion(l):
n = len(l)
if n<=1:
return l
else:
lg,ld = divise(l)
lg,ld = triFusion(lg),triFusion(ld)
return fusion(lg,ld)
## Quicksort
def partition(l):
lg = []
ld = []
pivot = l[0]
for elem in l[1:]:
if elem < pivot:
lg.append(elem)
else:
ld.append(elem)
return lg,ld,pivot
def quicksort(l):
n = len(l)
if n <= 1:
return l
else:
lg,ld,pivot = partition(l)
lg = quicksort(lg)
ld = quicksort(ld)
return lg+[pivot]+ld
## Quicksort + insertion
def sedgesort(l):
n = len(l)
if n<=15:
return triInsertionMieux(l)
else:
lg,ld,pivot = partition(l)
lg = sedgesort(lg)
ld = sedgesort(ld)
return(lg+[pivot]+ld)
## Mediane
def nth_least(l,n):
lg,ld,pivot = partition(l)
kg = len(lg)
if n==kg:
return pivot
elif n<kg:
return nth_least(lg,n)
else:
return nth_least(ld,n-(kg+1))
def mediane(l):
n = len(l)
return nth_least(l,n//2)
## Test
import random as rd
import time
l = [rd.randint(-499,499) for _ in range(20000)]
t = time.time()
l_insert = triInsertion(l)
print("Tri par insertion :",time.time() - t)
t = time.time()
l_insertmieux = triInsertionMieux(l)
print("Tri par insertion mieux :",time.time() - t)
t = time.time()
l_fusion = triFusion(l)
print("Tri fusion :",time.time() - t)
t = time.time()
l_qs = quicksort(l)
print("Tri rapide :",time.time() - t)
t = time.time()
l_sedge = sedgesort(l)
print("Tri Sedge :",time.time() - t)
t = time.time()
l_sort = sorted(l)
print("Tri Python :",time.time() - t)
t = time.time()
Ces documents ne concernent pas mes étudiants actuels, mais peuvent continuer d'intéresser certaines personnes.