from itertools import permutations
def tuples_sum(nbval,total,order=True) :
"""
Generate all the tuples L of nbval positive or nul integer
such that sum(L)=total.
The tuples may be ordered (decreasing order) or not
"""
if nbval == 0 and total == 0 : yield tuple() ; raise StopIteration
if nbval == 1 : yield (total,) ; raise StopIteration
if total==0 : yield (0,)*nbval ; raise StopIteration
for start in range(total,0,-1) :
for qu in tuples_sum(nbval-1,total-start) :
if qu[0]<=start :
sol=(start,)+qu
if order : yield sol
else :
l=set()
for p in permutations(sol,len(sol)) :
if p not in l :
l.add(p)
yield p
if __name__=='__main__' :
print("How to obtain 5 by adding a+b+c (>=0) ? ")
print("Give me the list of (a,b,c) tuples.")
g=tuples_sum(3,5,order=False)
print(list(g))
print("How to obtain 6 by adding 3 positive or nul integers ?")
g=tuples_sum(3,6,order=True)
print(list(g))
Diff to Previous Revision
--- revision 2 2013-07-16 14:01:28
+++ revision 3 2013-07-16 14:03:08
@@ -1,6 +1,6 @@
from itertools import permutations
-def genere(nbval,total,order=True) :
+def tuples_sum(nbval,total,order=True) :
"""
Generate all the tuples L of nbval positive or nul integer
such that sum(L)=total.
@@ -10,7 +10,7 @@
if nbval == 1 : yield (total,) ; raise StopIteration
if total==0 : yield (0,)*nbval ; raise StopIteration
for start in range(total,0,-1) :
- for qu in genere(nbval-1,total-start) :
+ for qu in tuples_sum(nbval-1,total-start) :
if qu[0]<=start :
sol=(start,)+qu
if order : yield sol
@@ -24,9 +24,9 @@
if __name__=='__main__' :
print("How to obtain 5 by adding a+b+c (>=0) ? ")
print("Give me the list of (a,b,c) tuples.")
- g=genere(3,5,order=False)
+ g=tuples_sum(3,5,order=False)
print(list(g))
print("How to obtain 6 by adding 3 positive or nul integers ?")
- g=genere(3,6,order=True)
+ g=tuples_sum(3,6,order=True)
print(list(g))
