Infinite loop while trying to determine the injectivity of a list [duplicate]
This question already has an answer here:
Convert from “For-loops” to “While-loops”
3 answers
For a school work, we have to create a function that determines if a list is injective, which returns True or False. 2 ways of doing the job are recommended : with 'for' loops and with 'while' loops. I managed to program with 'for' loops, but I'm having issues with 'while' loops, as i cannot figure out why mine is infinite.
I'll put my code below. I already tried getting rid of few variables that where needless, and as I modify the value of 'a' within the loop, it seems to me there is nothing wrong on paper.
def injective(x):
i=0
k=i+1
a=True
while i<len(L)-1 : #L is the name of the list
while k<len(L) :
if L[i]==L[k] :
a=False
else :
a=True
i+=1
return a
I expect to get True when the list is injective and False when not
python loops
asked Dec 28 '18 at 18:01
kiki ferkiki fer
33
marked as duplicate by Community♦ Dec 28 '18 at 18:25
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
add a comment |
This question already has an answer here:
Convert from “For-loops” to “While-loops”
3 answers
For a school work, we have to create a function that determines if a list is injective, which returns True or False. 2 ways of doing the job are recommended : with 'for' loops and with 'while' loops. I managed to program with 'for' loops, but I'm having issues with 'while' loops, as i cannot figure out why mine is infinite.
I'll put my code below. I already tried getting rid of few variables that where needless, and as I modify the value of 'a' within the loop, it seems to me there is nothing wrong on paper.
def injective(x):
i=0
k=i+1
a=True
while i<len(L)-1 : #L is the name of the list
while k<len(L) :
if L[i]==L[k] :
a=False
else :
a=True
i+=1
return a
I expect to get True when the list is injective and False when not
python loops
asked Dec 28 '18 at 18:01
kiki ferkiki fer
33
marked as duplicate by Community♦ Dec 28 '18 at 18:25
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
1
put k+=1 inside while k<len(L) loop and i+=1 in outer while loop
– prashant rana
Dec 28 '18 at 18:04
Lisxor something else?
– Anto Jurković
Dec 28 '18 at 18:04
converting aforloop to awhileloop would be an easier approach if you have that working. anyways, your innermost loop is never modifying the value ofkso the condition never becomes false. as a tip, if you can do it in aforloop, make sure you convert each for loop to awhileloop by resetting and incrementing at the right levels.
– Paritosh Singh
Dec 28 '18 at 18:04
Thank you for the help I see what i forgot.
– kiki fer
Dec 28 '18 at 18:08
The title given to your question is unlikely to be useful for anybody searching for answers about a similar problem. The question not abot injectivity of a list, but about how to convert for loops to while loops. This already has answers on SO, e.g. here.
– Adrian W
Dec 28 '18 at 18:12
add a comment |
This question already has an answer here:
Convert from “For-loops” to “While-loops”
3 answers
For a school work, we have to create a function that determines if a list is injective, which returns True or False. 2 ways of doing the job are recommended : with 'for' loops and with 'while' loops. I managed to program with 'for' loops, but I'm having issues with 'while' loops, as i cannot figure out why mine is infinite.
I'll put my code below. I already tried getting rid of few variables that where needless, and as I modify the value of 'a' within the loop, it seems to me there is nothing wrong on paper.
def injective(x):
i=0
k=i+1
a=True
while i<len(L)-1 : #L is the name of the list
while k<len(L) :
if L[i]==L[k] :
a=False
else :
a=True
i+=1
return a
I expect to get True when the list is injective and False when not
python loops
asked Dec 28 '18 at 18:01
kiki ferkiki fer
33
This question already has an answer here:
Convert from “For-loops” to “While-loops”
3 answers
For a school work, we have to create a function that determines if a list is injective, which returns True or False. 2 ways of doing the job are recommended : with 'for' loops and with 'while' loops. I managed to program with 'for' loops, but I'm having issues with 'while' loops, as i cannot figure out why mine is infinite.
I'll put my code below. I already tried getting rid of few variables that where needless, and as I modify the value of 'a' within the loop, it seems to me there is nothing wrong on paper.
def injective(x):
i=0
k=i+1
a=True
while i<len(L)-1 : #L is the name of the list
while k<len(L) :
if L[i]==L[k] :
a=False
else :
a=True
i+=1
return a
I expect to get True when the list is injective and False when not
This question already has an answer here:
Convert from “For-loops” to “While-loops”
3 answers
python loops
python loops
asked Dec 28 '18 at 18:01
kiki ferkiki fer
33
asked Dec 28 '18 at 18:01
kiki ferkiki fer
33
asked Dec 28 '18 at 18:01
kiki ferkiki fer
33
asked Dec 28 '18 at 18:01
kiki ferkiki fer
33
asked Dec 28 '18 at 18:01
kiki ferkiki fer
33
33
marked as duplicate by Community♦ Dec 28 '18 at 18:25
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
marked as duplicate by Community♦ Dec 28 '18 at 18:25
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
1
put k+=1 inside while k<len(L) loop and i+=1 in outer while loop
– prashant rana
Dec 28 '18 at 18:04
Lisxor something else?
– Anto Jurković
Dec 28 '18 at 18:04
converting aforloop to awhileloop would be an easier approach if you have that working. anyways, your innermost loop is never modifying the value ofkso the condition never becomes false. as a tip, if you can do it in aforloop, make sure you convert each for loop to awhileloop by resetting and incrementing at the right levels.
– Paritosh Singh
Dec 28 '18 at 18:04
Thank you for the help I see what i forgot.
– kiki fer
Dec 28 '18 at 18:08
The title given to your question is unlikely to be useful for anybody searching for answers about a similar problem. The question not abot injectivity of a list, but about how to convert for loops to while loops. This already has answers on SO, e.g. here.
– Adrian W
Dec 28 '18 at 18:12
add a comment |
1
put k+=1 inside while k<len(L) loop and i+=1 in outer while loop
– prashant rana
Dec 28 '18 at 18:04
Lisxor something else?
– Anto Jurković
Dec 28 '18 at 18:04
converting aforloop to awhileloop would be an easier approach if you have that working. anyways, your innermost loop is never modifying the value ofkso the condition never becomes false. as a tip, if you can do it in aforloop, make sure you convert each for loop to awhileloop by resetting and incrementing at the right levels.
– Paritosh Singh
Dec 28 '18 at 18:04
Thank you for the help I see what i forgot.
– kiki fer
Dec 28 '18 at 18:08
The title given to your question is unlikely to be useful for anybody searching for answers about a similar problem. The question not abot injectivity of a list, but about how to convert for loops to while loops. This already has answers on SO, e.g. here.
– Adrian W
Dec 28 '18 at 18:12
1
1
put k+=1 inside while k<len(L) loop and i+=1 in outer while loop
– prashant rana
Dec 28 '18 at 18:04
put k+=1 inside while k<len(L) loop and i+=1 in outer while loop
– prashant rana
Dec 28 '18 at 18:04
L is x or something else?– Anto Jurković
Dec 28 '18 at 18:04
L is x or something else?– Anto Jurković
Dec 28 '18 at 18:04
converting a
for loop to a while loop would be an easier approach if you have that working. anyways, your innermost loop is never modifying the value of k so the condition never becomes false. as a tip, if you can do it in a for loop, make sure you convert each for loop to a while loop by resetting and incrementing at the right levels.– Paritosh Singh
Dec 28 '18 at 18:04
converting a
for loop to a while loop would be an easier approach if you have that working. anyways, your innermost loop is never modifying the value of k so the condition never becomes false. as a tip, if you can do it in a for loop, make sure you convert each for loop to a while loop by resetting and incrementing at the right levels.– Paritosh Singh
Dec 28 '18 at 18:04
Thank you for the help I see what i forgot.
– kiki fer
Dec 28 '18 at 18:08
Thank you for the help I see what i forgot.
– kiki fer
Dec 28 '18 at 18:08
The title given to your question is unlikely to be useful for anybody searching for answers about a similar problem. The question not abot injectivity of a list, but about how to convert for loops to while loops. This already has answers on SO, e.g. here.
– Adrian W
Dec 28 '18 at 18:12
The title given to your question is unlikely to be useful for anybody searching for answers about a similar problem. The question not abot injectivity of a list, but about how to convert for loops to while loops. This already has answers on SO, e.g. here.
– Adrian W
Dec 28 '18 at 18:12
add a comment |
1 Answer
1
active
oldest
votes
It is because the value of k in the inner loop is not changing, I think you are missing k+=1 somewhere.
Code
def injective(x):
i=0
k=i+1
while i<len(L)-1 : #L is the name of the list
while k<len(L) :
if L[i]==L[k] :
return False
k+=1
i+=1
return True
I have taken the liberty to optimize the code a bit (it will decrease your iterations drastically for a non-injective function). You can use the same in your other program with the for loop.
answered Dec 28 '18 at 18:04
javan.rajpopatjavan.rajpopat
1514
1
This is similar to what I have for my for loop, thank you for the help
– kiki fer
Dec 28 '18 at 18:13
One more thing, I am not sure why you need 'len(L)-1' in the outer loop, I think you will need to check the last element also. (not sure though)
– javan.rajpopat
Dec 28 '18 at 18:15
Isn't the last element checked with the first iteration ?
– kiki fer
Dec 28 '18 at 18:19
add a comment |
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
It is because the value of k in the inner loop is not changing, I think you are missing k+=1 somewhere.
Code
def injective(x):
i=0
k=i+1
while i<len(L)-1 : #L is the name of the list
while k<len(L) :
if L[i]==L[k] :
return False
k+=1
i+=1
return True
I have taken the liberty to optimize the code a bit (it will decrease your iterations drastically for a non-injective function). You can use the same in your other program with the for loop.
answered Dec 28 '18 at 18:04
javan.rajpopatjavan.rajpopat
1514
1
This is similar to what I have for my for loop, thank you for the help
– kiki fer
Dec 28 '18 at 18:13
One more thing, I am not sure why you need 'len(L)-1' in the outer loop, I think you will need to check the last element also. (not sure though)
– javan.rajpopat
Dec 28 '18 at 18:15
Isn't the last element checked with the first iteration ?
– kiki fer
Dec 28 '18 at 18:19
add a comment |
It is because the value of k in the inner loop is not changing, I think you are missing k+=1 somewhere.
Code
def injective(x):
i=0
k=i+1
while i<len(L)-1 : #L is the name of the list
while k<len(L) :
if L[i]==L[k] :
return False
k+=1
i+=1
return True
I have taken the liberty to optimize the code a bit (it will decrease your iterations drastically for a non-injective function). You can use the same in your other program with the for loop.
answered Dec 28 '18 at 18:04
javan.rajpopatjavan.rajpopat
1514
1
This is similar to what I have for my for loop, thank you for the help
– kiki fer
Dec 28 '18 at 18:13
One more thing, I am not sure why you need 'len(L)-1' in the outer loop, I think you will need to check the last element also. (not sure though)
– javan.rajpopat
Dec 28 '18 at 18:15
Isn't the last element checked with the first iteration ?
– kiki fer
Dec 28 '18 at 18:19
add a comment |
It is because the value of k in the inner loop is not changing, I think you are missing k+=1 somewhere.
Code
def injective(x):
i=0
k=i+1
while i<len(L)-1 : #L is the name of the list
while k<len(L) :
if L[i]==L[k] :
return False
k+=1
i+=1
return True
I have taken the liberty to optimize the code a bit (it will decrease your iterations drastically for a non-injective function). You can use the same in your other program with the for loop.
answered Dec 28 '18 at 18:04
javan.rajpopatjavan.rajpopat
1514
It is because the value of k in the inner loop is not changing, I think you are missing k+=1 somewhere.
Code
def injective(x):
i=0
k=i+1
while i<len(L)-1 : #L is the name of the list
while k<len(L) :
if L[i]==L[k] :
return False
k+=1
i+=1
return True
I have taken the liberty to optimize the code a bit (it will decrease your iterations drastically for a non-injective function). You can use the same in your other program with the for loop.
answered Dec 28 '18 at 18:04
javan.rajpopatjavan.rajpopat
1514
edited Dec 28 '18 at 18:12
answered Dec 28 '18 at 18:04
javan.rajpopatjavan.rajpopat
1514
answered Dec 28 '18 at 18:04
javan.rajpopatjavan.rajpopat
1514
answered Dec 28 '18 at 18:04
javan.rajpopatjavan.rajpopat
1514
1514
1
This is similar to what I have for my for loop, thank you for the help
– kiki fer
Dec 28 '18 at 18:13
One more thing, I am not sure why you need 'len(L)-1' in the outer loop, I think you will need to check the last element also. (not sure though)
– javan.rajpopat
Dec 28 '18 at 18:15
Isn't the last element checked with the first iteration ?
– kiki fer
Dec 28 '18 at 18:19
add a comment |
1
This is similar to what I have for my for loop, thank you for the help
– kiki fer
Dec 28 '18 at 18:13
One more thing, I am not sure why you need 'len(L)-1' in the outer loop, I think you will need to check the last element also. (not sure though)
– javan.rajpopat
Dec 28 '18 at 18:15
Isn't the last element checked with the first iteration ?
– kiki fer
Dec 28 '18 at 18:19
1
1
This is similar to what I have for my for loop, thank you for the help
– kiki fer
Dec 28 '18 at 18:13
This is similar to what I have for my for loop, thank you for the help
– kiki fer
Dec 28 '18 at 18:13
One more thing, I am not sure why you need 'len(L)-1' in the outer loop, I think you will need to check the last element also. (not sure though)
– javan.rajpopat
Dec 28 '18 at 18:15
One more thing, I am not sure why you need 'len(L)-1' in the outer loop, I think you will need to check the last element also. (not sure though)
– javan.rajpopat
Dec 28 '18 at 18:15
Isn't the last element checked with the first iteration ?
– kiki fer
Dec 28 '18 at 18:19
Isn't the last element checked with the first iteration ?
– kiki fer
Dec 28 '18 at 18:19
add a comment |
1
put k+=1 inside while k<len(L) loop and i+=1 in outer while loop
– prashant rana
Dec 28 '18 at 18:04
Lisxor something else?– Anto Jurković
Dec 28 '18 at 18:04
converting a
forloop to awhileloop would be an easier approach if you have that working. anyways, your innermost loop is never modifying the value ofkso the condition never becomes false. as a tip, if you can do it in aforloop, make sure you convert each for loop to awhileloop by resetting and incrementing at the right levels.– Paritosh Singh
Dec 28 '18 at 18:04
Thank you for the help I see what i forgot.
– kiki fer
Dec 28 '18 at 18:08
The title given to your question is unlikely to be useful for anybody searching for answers about a similar problem. The question not abot injectivity of a list, but about how to convert for loops to while loops. This already has answers on SO, e.g. here.
– Adrian W
Dec 28 '18 at 18:12