# Untitled

unknown
python
2 years ago
1.4 kB
0
Indexable
Never
```def find_132(nums):
smallest_on_left = nums[0]
for idx in range(1, len(nums)-1):
i = smallest_on_left
j = nums[idx]
smallest_on_left = min(smallest_on_left, j)
if j <= i:
continue
for idx2 in range(idx+1, len(nums)):
if (nums[idx2] > i) and (nums[idx2] < j):
return True
return False

print(find_132([1,2,3,4]))
print(find_132([3,1,4,2]))
print(find_132([-1,3,2,0]))

def find_132_v2(nums):
valid_ijs = []
valid_ijs.append([nums[0], None])
for idx in range(1, len(nums)):
new_num = nums[idx]

# Check validity of existing pairs
for pair in valid_ijs:
if pair[1] is not None:
if (pair[0]<new_num) and (pair[1]>new_num):
return True

# Update pairs on new number
if new_num<min([x[0] for x in valid_ijs]):
valid_ijs = [x for x in valid_ijs if x[1] is not None]
valid_ijs.append([new_num, None])
continue
for pair in valid_ijs:
if pair[1] is None:
pair[1] = new_num
else:
pair[1] = max(pair[1], new_num)
return False

print(find_132_v2([1,2,3,4]))
print(find_132_v2([3,1,4,2]))
print(find_132_v2([-1,3,2,0]))```