# Python: Find the indices of the closest pair from given a list of numbers

## Python Programming Puzzles: Exercise-66 with Solution

Write a Python program to find the indices of the closest pair from a list of numbers.

Input: [1, 7, 9, 2, 10] Output: [0, 3] Input: [1.1, 4.25, 0.79, 1.0, 4.23] Output: [4, 1] Input: [0.21, 11.3, 2.01, 8.0, 10.0, 3.0, 15.2] Output: [2, 5]

**Visual Presentation:**

**Sample Solution:**

**Python Code:**

```
# License: https://bit.ly/3oLErEI
def test(nums):
# Initialize variables to store indices of the closest pair and the closest distance
closest_inds = None
closest_dist = None
# Iterate through each element in the list
for ind, num in enumerate(nums):
# Compare each element with every other element in the list
for other_ind, num2 in enumerate(nums):
# Check if the elements are distinct and calculate the absolute difference
if num != num2 and ((closest_dist is None) or abs(num - num2) < closest_dist):
# Update the closest distance and indices
closest_dist = abs(num - num2)
# Determine the order of indices based on the magnitude of the numbers
if num <= num2:
closest_inds = [ind, other_ind]
else:
closest_inds = [other_ind, ind]
# Return the indices of the closest pair
return closest_inds
# Example 1
nums1 = [1, 7, 9, 2, 10]
print("List of numbers:", nums1)
print("Indices of the closest pair from the said list of numbers:")
print(test(nums1))
# Example 2
nums2 = [1.1, 4.25, 0.79, 1.0, 4.23]
print("\nList of numbers:", nums2)
print("Indices of the closest pair from the said list of numbers:")
print(test(nums2))
# Example 3
nums3 = [0.21, 11.3, 2.01, 8.0, 10.0, 3.0, 15.2]
print("\nList of numbers:", nums3)
print("Indices of the closest pair from the said list of numbers:")
print(test(nums3))
```

Sample Output:

List of numbers: [1, 7, 9, 2, 10] Indices of the closest pair from the said list of numbers: [0, 3] List of numbers: [1.1, 4.25, 0.79, 1.0, 4.23] Indices of the closest pair from the said list of numbers: [4, 1] List of numbers: [0.21, 11.3, 2.01, 8.0, 10.0, 3.0, 15.2] Indices of the closest pair from the said list of numbers: [2, 5]

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