Python | Check whether two lists follow same pattern or not

Given two lists and , check if they follow the same pattern or not. Condition for pattern matching:

1. > , then >
2. = , then =
3. < , then < , for all i, j.

Example:

Input: 2 17 100 10 20 50 Output: YES Input: 5 7 10 33 10 50 10 45 Output: NO

Approach: To check if two lists follow the above pattern. Sort both lists and find the index of previous list element in the sorted list. If indices match, then pattern matched otherwise no pattern matched. Code : Python program for checking the pattern.

# python program for above approach
a = [5, 7, 10, 33]
b = [10, 50, 10, 45]
aa = a.copy()
bb = b.copy()

# sorting the list
aa.sort()
bb.sort()

for i in range(len(a)-1):

    # checking the index are same or not
    if aa[i] < aa[i + 1] and bb[i] < bb[i + 1]:
        if a.index(aa[i])== b.index(bb[i]) and a.index(aa[i + 1]) == b.index(bb[i + 1]):
            flag ="YES"
        else:
            flag ="NO"
            break

    elif aa[i] == aa[i + 1] and bb[i] == bb[i + 1]:
        if a.index(aa[i]) == b.index(bb[i]) and a.index(aa[i + 1]) == b.index(bb[i + 1]):
            flag = "YES"
        else:
            flag = "NO"
            break

    else:
        flag = "NO"
        break

print(flag)

Output :

NO