import sys
def find_closest_to_zero(lst):
if len(lst) < 2:
print("list must have at least two elements.")
return
# Step 1: Sort the list
sorted_lst = sorted(lst)
left = 0
right = len(sorted_lst) - 1
closest_sum = sys.maxsize # Equivalent to INT_MAX
closest_pair = [0, 0]
# Step 2: Use two-indexed technique
while left < right:
sum_ = sorted_lst[left] + sorted_lst[right]
# Update closest sum and pair if needed
if abs(sum_) < abs(closest_sum):
closest_sum = sum_
closest_pair[0] = sorted_lst[left]
closest_pair[1] = sorted_lst[right]
# Move indexeds
if sum_ < 0:
left += 1 # Increase sum by moving left indexed
else:
right -= 1 # Decrease sum by moving right indexed
# Output the result
print(f"The two elements whose sum is closest to zero are: "
f"{closest_pair[0]} and {closest_pair[1]} with a sum of {closest_sum}.")
lst = [23, -26, -88, -42, 55, 99, -11, 90, -13, 17, -31]
find_closest_to_zero(lst)
'''
run:
The two elements whose sum is closest to zero are: -88 and 90 with a sum of 2.
'''
