num = [100, 10, 200, 25, 7, 20]
    l = len(num)
    i = 0
    min = 0
    while i < l:
        j = i 1
        while j < l:
            ans = num[i] - num[j]
            print(f'{num[i]} diff {num[j]} is {ans}')
            j  = 1
        i  = 1

The output should be the lowest difference which should be 3 for this problem.

I know how to get all the difference but I don't know how to filter out the smallest difference.

CodePudding user response：

You may first sort it, and then loop through it for least difference.

num = [100, 10, 200, 25, 7, 20]
num.sort()
least_diff=None
for i in range(len(num)-1):
    diff=abs(num[i]-num[i 1])
    if not least_diff:
        least_diff=diff
    if diff<least_diff:
        least_diff=diff
print(least_diff)

Output:

3

CodePudding user response：

There's two issues that you probably need to deal with in finding the minimum difference using this technique:

• retaining the minimum as you generate the individual differences
• taking the absolute value of the difference (if that's what you want)

Couple of side notes: it is really confusing to use the single letter l as a variable name, given its resemblance to the digit 1. And min is a built-in function so using that as variable name, while totally legal, can also be confusing.

So, within your flow structure, and using just built-in facilities rather than libraries, you could write:

    num = [100, 10, 200, 25, 7, 20]
    sz = len(num)
    i = 0
    ans = abs(num[1]-num[0]) # initialize to a possible value
    while i < sz:
        j = i 1
        while j < sz:
            diff = abs(num[i] - num[j]) # take positive diff using abs built-in function
            # print(f'{num[i]} diff {num[j]} is {diff}')
            if diff < ans: # or could use min function or in-line-if
                ans = diff 
            j  = 1
        i  = 1