How to check if one or two integers are -1, among four integer variables in total, Python3?
I have 4 integer variables
r1, r2, c1, c2
They can be any integer values. I want to find out which of them is/are -1.
The rule is r1 and r2 cannot be -1 at the same time; c1 and c2 cannot be -1 at the same time.
I can use if statement, but it can be cumbersome:
if r1 == -1:
if c1 == -1:
# do action a
elif c2 == -1:
# do action b
else: # c1 and c2 are both not -1
# do action c
elif r2 == -1:
if c1 == -1:
# do action d
elif c2 == -1:
# do action e
else: # c1 and c2 are both not -1
# do action f
else: # none of the four integers is -1.
# do action g
Could you please show me some more elegant and efficient algorithm?
python python-3.x if-statement
edited Nov 20 '18 at 16:16
gsamaras
50.6k2399186
asked Nov 20 '18 at 16:08
aura
1679
|
show 3 more comments
I have 4 integer variables
r1, r2, c1, c2
They can be any integer values. I want to find out which of them is/are -1.
The rule is r1 and r2 cannot be -1 at the same time; c1 and c2 cannot be -1 at the same time.
I can use if statement, but it can be cumbersome:
if r1 == -1:
if c1 == -1:
# do action a
elif c2 == -1:
# do action b
else: # c1 and c2 are both not -1
# do action c
elif r2 == -1:
if c1 == -1:
# do action d
elif c2 == -1:
# do action e
else: # c1 and c2 are both not -1
# do action f
else: # none of the four integers is -1.
# do action g
Could you please show me some more elegant and efficient algorithm?
python python-3.x if-statement
edited Nov 20 '18 at 16:16
gsamaras
50.6k2399186
asked Nov 20 '18 at 16:08
aura
1679
3
This logic seems suspect: the comment# none of the four integers is -1.is incorrect.
– wim
Nov 20 '18 at 16:16
3
Do you just need to check thatr1,r2are both not -1 andc1,c2are not -1 ?
– Austin
Nov 20 '18 at 16:23
6
If you want to perform specific operations depending on value of each variable thenif elsemight be the only way!
– Sandesh34
Nov 20 '18 at 16:26
if r1 == r2 == -1 or c1 == c2 == -1: print("rule violation")
– jasonharper
Nov 20 '18 at 17:12
@Sandesh.Patil I can actually think of a few ways that doesn't involveif... else...but none of them would be as readable and as elegant as the original implementation. That said, if OP confirms it's just a check against-1and no separate actions needed, it'll be much simpler.
– Idlehands
Nov 20 '18 at 17:33
|
show 3 more comments
I have 4 integer variables
r1, r2, c1, c2
They can be any integer values. I want to find out which of them is/are -1.
The rule is r1 and r2 cannot be -1 at the same time; c1 and c2 cannot be -1 at the same time.
I can use if statement, but it can be cumbersome:
if r1 == -1:
if c1 == -1:
# do action a
elif c2 == -1:
# do action b
else: # c1 and c2 are both not -1
# do action c
elif r2 == -1:
if c1 == -1:
# do action d
elif c2 == -1:
# do action e
else: # c1 and c2 are both not -1
# do action f
else: # none of the four integers is -1.
# do action g
Could you please show me some more elegant and efficient algorithm?
python python-3.x if-statement
edited Nov 20 '18 at 16:16
gsamaras
50.6k2399186
asked Nov 20 '18 at 16:08
aura
1679
I have 4 integer variables
r1, r2, c1, c2
They can be any integer values. I want to find out which of them is/are -1.
The rule is r1 and r2 cannot be -1 at the same time; c1 and c2 cannot be -1 at the same time.
I can use if statement, but it can be cumbersome:
if r1 == -1:
if c1 == -1:
# do action a
elif c2 == -1:
# do action b
else: # c1 and c2 are both not -1
# do action c
elif r2 == -1:
if c1 == -1:
# do action d
elif c2 == -1:
# do action e
else: # c1 and c2 are both not -1
# do action f
else: # none of the four integers is -1.
# do action g
Could you please show me some more elegant and efficient algorithm?
python python-3.x if-statement
python python-3.x if-statement
edited Nov 20 '18 at 16:16
gsamaras
50.6k2399186
asked Nov 20 '18 at 16:08
aura
1679
edited Nov 20 '18 at 16:16
gsamaras
50.6k2399186
asked Nov 20 '18 at 16:08
aura
1679
edited Nov 20 '18 at 16:16
gsamaras
50.6k2399186
edited Nov 20 '18 at 16:16
gsamaras
50.6k2399186
edited Nov 20 '18 at 16:16
gsamaras
50.6k2399186
50.6k2399186
asked Nov 20 '18 at 16:08
aura
1679
asked Nov 20 '18 at 16:08
aura
1679
asked Nov 20 '18 at 16:08
aura
1679
1679
3
This logic seems suspect: the comment# none of the four integers is -1.is incorrect.
– wim
Nov 20 '18 at 16:16
3
Do you just need to check thatr1,r2are both not -1 andc1,c2are not -1 ?
– Austin
Nov 20 '18 at 16:23
6
If you want to perform specific operations depending on value of each variable thenif elsemight be the only way!
– Sandesh34
Nov 20 '18 at 16:26
if r1 == r2 == -1 or c1 == c2 == -1: print("rule violation")
– jasonharper
Nov 20 '18 at 17:12
@Sandesh.Patil I can actually think of a few ways that doesn't involveif... else...but none of them would be as readable and as elegant as the original implementation. That said, if OP confirms it's just a check against-1and no separate actions needed, it'll be much simpler.
– Idlehands
Nov 20 '18 at 17:33
|
show 3 more comments
3
This logic seems suspect: the comment# none of the four integers is -1.is incorrect.
– wim
Nov 20 '18 at 16:16
3
Do you just need to check thatr1,r2are both not -1 andc1,c2are not -1 ?
– Austin
Nov 20 '18 at 16:23
6
If you want to perform specific operations depending on value of each variable thenif elsemight be the only way!
– Sandesh34
Nov 20 '18 at 16:26
if r1 == r2 == -1 or c1 == c2 == -1: print("rule violation")
– jasonharper
Nov 20 '18 at 17:12
@Sandesh.Patil I can actually think of a few ways that doesn't involveif... else...but none of them would be as readable and as elegant as the original implementation. That said, if OP confirms it's just a check against-1and no separate actions needed, it'll be much simpler.
– Idlehands
Nov 20 '18 at 17:33
3
3
This logic seems suspect: the comment
# none of the four integers is -1. is incorrect.– wim
Nov 20 '18 at 16:16
This logic seems suspect: the comment
# none of the four integers is -1. is incorrect.– wim
Nov 20 '18 at 16:16
3
3
Do you just need to check that
r1, r2 are both not -1 and c1, c2 are not -1 ?– Austin
Nov 20 '18 at 16:23
Do you just need to check that
r1, r2 are both not -1 and c1, c2 are not -1 ?– Austin
Nov 20 '18 at 16:23
6
6
If you want to perform specific operations depending on value of each variable then
if else might be the only way!– Sandesh34
Nov 20 '18 at 16:26
If you want to perform specific operations depending on value of each variable then
if else might be the only way!– Sandesh34
Nov 20 '18 at 16:26
if r1 == r2 == -1 or c1 == c2 == -1: print("rule violation")– jasonharper
Nov 20 '18 at 17:12
if r1 == r2 == -1 or c1 == c2 == -1: print("rule violation")– jasonharper
Nov 20 '18 at 17:12
@Sandesh.Patil I can actually think of a few ways that doesn't involve
if... else... but none of them would be as readable and as elegant as the original implementation. That said, if OP confirms it's just a check against -1 and no separate actions needed, it'll be much simpler.– Idlehands
Nov 20 '18 at 17:33
@Sandesh.Patil I can actually think of a few ways that doesn't involve
if... else... but none of them would be as readable and as elegant as the original implementation. That said, if OP confirms it's just a check against -1 and no separate actions needed, it'll be much simpler.– Idlehands
Nov 20 '18 at 17:33
|
show 3 more comments
2 Answers
2
active
oldest
votes
I don't think you have an efficiency problem here, but you can improve readability by checking for the two illegal scenarios you mentioned explicitly:
if r1 == -1 and r2 == -1:
raise Exception("r1 & r2 are -1")
elif c1 == -1 and c2 == -1:
raise Exception("c1 & c2 are -1")
else:
print("ok!")
You have some options to avoid the if/else entirely (a dictionary, for instance, with keys as tuples of (r1, r2, c1, c2) and the operations you wish to invoke as values), but I think they would all be a net loss insofar as readability goes.
answered Nov 20 '18 at 17:15
chris
823814
I think you're just adding more statements, since he wants to perform various operations. And he's in need of efficient one
– Sandesh34
Nov 20 '18 at 17:23
add a comment |
Based upon the rules you mentioned i.e. it cannot happen that r1=r2=-1 and c1=c2=-1, we can assume that there are cases when we do not need to perform all four checks to find out if your variables are -1 or not.
In order to utilize these rules, you need to have some data structure that reflects order of your variables and enables to skip checks that are not required (e.g. r1 = -1 than we do not need to check r2).
While this perhaps is not more efficient CPU time-wise, it follows the logic that it is not necessary to perform all of the variable checks in each scenario:
d = {'r1' : 0, 'r2' : -1, 'c1' : -1, 'c2' : 0}
def isMinusOne(x):
if x == -1:
return x
i = 0
while i < len(d):
if isMinusOne(list(d.values())[i]) is not None:
print(list(d.keys())[i])
if i == 0 or i == 2:
i += 2
else:
i += 1
else:
i += 1
answered Nov 20 '18 at 17:30
New2Python
338113
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
I don't think you have an efficiency problem here, but you can improve readability by checking for the two illegal scenarios you mentioned explicitly:
if r1 == -1 and r2 == -1:
raise Exception("r1 & r2 are -1")
elif c1 == -1 and c2 == -1:
raise Exception("c1 & c2 are -1")
else:
print("ok!")
You have some options to avoid the if/else entirely (a dictionary, for instance, with keys as tuples of (r1, r2, c1, c2) and the operations you wish to invoke as values), but I think they would all be a net loss insofar as readability goes.
answered Nov 20 '18 at 17:15
chris
823814
I think you're just adding more statements, since he wants to perform various operations. And he's in need of efficient one
– Sandesh34
Nov 20 '18 at 17:23
add a comment |
I don't think you have an efficiency problem here, but you can improve readability by checking for the two illegal scenarios you mentioned explicitly:
if r1 == -1 and r2 == -1:
raise Exception("r1 & r2 are -1")
elif c1 == -1 and c2 == -1:
raise Exception("c1 & c2 are -1")
else:
print("ok!")
You have some options to avoid the if/else entirely (a dictionary, for instance, with keys as tuples of (r1, r2, c1, c2) and the operations you wish to invoke as values), but I think they would all be a net loss insofar as readability goes.
answered Nov 20 '18 at 17:15
chris
823814
I think you're just adding more statements, since he wants to perform various operations. And he's in need of efficient one
– Sandesh34
Nov 20 '18 at 17:23
add a comment |
I don't think you have an efficiency problem here, but you can improve readability by checking for the two illegal scenarios you mentioned explicitly:
if r1 == -1 and r2 == -1:
raise Exception("r1 & r2 are -1")
elif c1 == -1 and c2 == -1:
raise Exception("c1 & c2 are -1")
else:
print("ok!")
You have some options to avoid the if/else entirely (a dictionary, for instance, with keys as tuples of (r1, r2, c1, c2) and the operations you wish to invoke as values), but I think they would all be a net loss insofar as readability goes.
answered Nov 20 '18 at 17:15
chris
823814
I don't think you have an efficiency problem here, but you can improve readability by checking for the two illegal scenarios you mentioned explicitly:
if r1 == -1 and r2 == -1:
raise Exception("r1 & r2 are -1")
elif c1 == -1 and c2 == -1:
raise Exception("c1 & c2 are -1")
else:
print("ok!")
You have some options to avoid the if/else entirely (a dictionary, for instance, with keys as tuples of (r1, r2, c1, c2) and the operations you wish to invoke as values), but I think they would all be a net loss insofar as readability goes.
answered Nov 20 '18 at 17:15
chris
823814
edited Nov 20 '18 at 17:39
answered Nov 20 '18 at 17:15
chris
823814
answered Nov 20 '18 at 17:15
chris
823814
answered Nov 20 '18 at 17:15
chris
823814
823814
I think you're just adding more statements, since he wants to perform various operations. And he's in need of efficient one
– Sandesh34
Nov 20 '18 at 17:23
add a comment |
I think you're just adding more statements, since he wants to perform various operations. And he's in need of efficient one
– Sandesh34
Nov 20 '18 at 17:23
I think you're just adding more statements, since he wants to perform various operations. And he's in need of efficient one
– Sandesh34
Nov 20 '18 at 17:23
I think you're just adding more statements, since he wants to perform various operations. And he's in need of efficient one
– Sandesh34
Nov 20 '18 at 17:23
add a comment |
Based upon the rules you mentioned i.e. it cannot happen that r1=r2=-1 and c1=c2=-1, we can assume that there are cases when we do not need to perform all four checks to find out if your variables are -1 or not.
In order to utilize these rules, you need to have some data structure that reflects order of your variables and enables to skip checks that are not required (e.g. r1 = -1 than we do not need to check r2).
While this perhaps is not more efficient CPU time-wise, it follows the logic that it is not necessary to perform all of the variable checks in each scenario:
d = {'r1' : 0, 'r2' : -1, 'c1' : -1, 'c2' : 0}
def isMinusOne(x):
if x == -1:
return x
i = 0
while i < len(d):
if isMinusOne(list(d.values())[i]) is not None:
print(list(d.keys())[i])
if i == 0 or i == 2:
i += 2
else:
i += 1
else:
i += 1
answered Nov 20 '18 at 17:30
New2Python
338113
add a comment |
Based upon the rules you mentioned i.e. it cannot happen that r1=r2=-1 and c1=c2=-1, we can assume that there are cases when we do not need to perform all four checks to find out if your variables are -1 or not.
In order to utilize these rules, you need to have some data structure that reflects order of your variables and enables to skip checks that are not required (e.g. r1 = -1 than we do not need to check r2).
While this perhaps is not more efficient CPU time-wise, it follows the logic that it is not necessary to perform all of the variable checks in each scenario:
d = {'r1' : 0, 'r2' : -1, 'c1' : -1, 'c2' : 0}
def isMinusOne(x):
if x == -1:
return x
i = 0
while i < len(d):
if isMinusOne(list(d.values())[i]) is not None:
print(list(d.keys())[i])
if i == 0 or i == 2:
i += 2
else:
i += 1
else:
i += 1
answered Nov 20 '18 at 17:30
New2Python
338113
add a comment |
Based upon the rules you mentioned i.e. it cannot happen that r1=r2=-1 and c1=c2=-1, we can assume that there are cases when we do not need to perform all four checks to find out if your variables are -1 or not.
In order to utilize these rules, you need to have some data structure that reflects order of your variables and enables to skip checks that are not required (e.g. r1 = -1 than we do not need to check r2).
While this perhaps is not more efficient CPU time-wise, it follows the logic that it is not necessary to perform all of the variable checks in each scenario:
d = {'r1' : 0, 'r2' : -1, 'c1' : -1, 'c2' : 0}
def isMinusOne(x):
if x == -1:
return x
i = 0
while i < len(d):
if isMinusOne(list(d.values())[i]) is not None:
print(list(d.keys())[i])
if i == 0 or i == 2:
i += 2
else:
i += 1
else:
i += 1
answered Nov 20 '18 at 17:30
New2Python
338113
Based upon the rules you mentioned i.e. it cannot happen that r1=r2=-1 and c1=c2=-1, we can assume that there are cases when we do not need to perform all four checks to find out if your variables are -1 or not.
In order to utilize these rules, you need to have some data structure that reflects order of your variables and enables to skip checks that are not required (e.g. r1 = -1 than we do not need to check r2).
While this perhaps is not more efficient CPU time-wise, it follows the logic that it is not necessary to perform all of the variable checks in each scenario:
d = {'r1' : 0, 'r2' : -1, 'c1' : -1, 'c2' : 0}
def isMinusOne(x):
if x == -1:
return x
i = 0
while i < len(d):
if isMinusOne(list(d.values())[i]) is not None:
print(list(d.keys())[i])
if i == 0 or i == 2:
i += 2
else:
i += 1
else:
i += 1
answered Nov 20 '18 at 17:30
New2Python
338113
edited Nov 20 '18 at 20:43
answered Nov 20 '18 at 17:30
New2Python
338113
answered Nov 20 '18 at 17:30
New2Python
338113
answered Nov 20 '18 at 17:30
New2Python
338113
338113
add a comment |
add a comment |
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3
This logic seems suspect: the comment
# none of the four integers is -1.is incorrect.– wim
Nov 20 '18 at 16:16
3
Do you just need to check that
r1,r2are both not -1 andc1,c2are not -1 ?– Austin
Nov 20 '18 at 16:23
6
If you want to perform specific operations depending on value of each variable then
if elsemight be the only way!– Sandesh34
Nov 20 '18 at 16:26
if r1 == r2 == -1 or c1 == c2 == -1: print("rule violation")– jasonharper
Nov 20 '18 at 17:12
@Sandesh.Patil I can actually think of a few ways that doesn't involve
if... else...but none of them would be as readable and as elegant as the original implementation. That said, if OP confirms it's just a check against-1and no separate actions needed, it'll be much simpler.– Idlehands
Nov 20 '18 at 17:33