CODEWITHSUNDEEP
pythonlistmax
user3742904
user3742904

Reputation: 27

max value of list without max() method

I need to find the max value of a list but I can't use the max() method. How would I go about doing this? I'm just a beginner so I'm sure this is pretty easy to find a workaround, however I'm stumped.

Edit: Forgot to mention that it's python I'm working in.

Upvotes: 0

Views: 67494

Answers (10)

dev_light
dev_light

Reputation: 3899

This is a code implementation of the algorithm described in @OlympusMonds answer. This is useful if you want to find the max value in a list without using the max() function or any other builtin:

num_list = [3, 1, 8, 0, 5, 9, 2, 4, 6, 7]
max_val = num_list[0]    # Initialise max_val and set it to the first item in the list
for num in num_list:    
    if num > max_val:
        max_val = num

You can print(max_val) to see that it returns the maximum value in the list. In this case, the output is 9.

Upvotes: 0

DarkTime
DarkTime

Reputation: 26

Here, we use the reduce function that is available in the built-in module called "functools", essentially "reduce" returns only one value, which in this case, is the maximum of the numbers. So, the main logic here is we return the current number if it's larger than the next number in the list, else we just return the next number if it doesn't satisfy the condition.

from functools import reduce
inp = input("Values separated by spaces: ")
arr = map(int, inp.split())
ans = reduce(lambda x, y: x if x > y else y, arr)
print(ans)

Upvotes: 1

Sudha Amarnath
Sudha Amarnath

Reputation: 1

s=[10,11,12,9,10,11]
length = len(s)-1
for i in range(length):
    if s[i] > s[i + 1]:
        s[i], s[i + 1] = s[i + 1], s[i]
print(s[-1]) #12

Upvotes: -1

Satya
Satya

Reputation: 1

input_string =input("Enter a list numbers or elements separated by space: ")
userList = input_string.split()

l=list((map(int, userList)))
print(l)

a = (len(l))
temp=0

for i in range(0,a-1):
  if l[i]>l[i+1]:
    c=l[i]
    if c>temp:
       temp=c

  else:
    c= l[i+1]  
    if c>temp:
       temp=c


print(temp)

Upvotes: -2

Some Dude
Some Dude

Reputation: 1

You could try this.....

my_list = [0, 2, 5, 6, 5, 8, 5, 8, 8]
my_max = [ ]
for list in my_list:
       if list > 7:
       my_max = my_max + [list]
Print(my_max)

This should output [8,8,8]

Upvotes: -2

imh1j4l
imh1j4l

Reputation: 95

def max(a):

    res = a[0]
    for i in a:
        if res < i:
            res = i
    return res

array = (1, 2, 3, 4, 5, 6)

print(max(array))

Upvotes: -2

Jamie Bull
Jamie Bull

Reputation: 13529

Simple one-liner in python:

max = sorted(my_list)[-1]

This puts the list in order from smallest to largest, then takes the final value which is the largest.

Upvotes: 1

McLovin
McLovin

Reputation: 3674

max = list[0]
for x in list:
    if x > max:
        max = x
print max

In this example, we initialize the max value to the first element. Then we iterate through the list, and if we find a larger value than the current max, we assign that value to max. At the end, we should have the largest value, which we print.

Upvotes: 10

OlympusMonds
OlympusMonds

Reputation: 158

Think about how you would do this manually.

If you had a list like this:

[10, 6, 8, 2, 4, 12, 3]

To find the max manually, you would start with the first number, 10, and that would be the max. Then you move to the next number, 6:

 M
[10, 6, 8, 2, 4, 12, 3]
     ^

Is it bigger than 10? No, then move to the next number:

 M
[10, 6, 8, 2, 4, 12, 3]
        ^

 M
[10, 6, 8, 2, 4, 12, 3]
           ^
 M
[10, 6, 8, 2, 4, 12, 3]
              ^
 M
[10, 6, 8, 2, 4, 12, 3]
                 ^

Now we come to a number that IS bigger than our max of 10. So then we move the max point:

                 M
[10, 6, 8, 2, 4, 12, 3]
                 ^

Then continue:

                 M
[10, 6, 8, 2, 4, 12, 3]
                     ^

The list is finished now, and M points at 12.

Now you just need to code it up!

Upvotes: 7

Dennis Degryse
Dennis Degryse

Reputation: 104

Sounds like homework to me, but perhaps some logics can help you out:

when you iterate the list, the point is that you want to know whether the current element is the MAX of all others. This can be solved by keeping the MAX up to the current element (say M*) and do a simple comparison between M* and your current element. Then update M* according to the result of that comparison. At the end of the iteration I think you can figure out where your MAX is.

Upvotes: 1

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