Python Practice › List Programs › Program 8
Pairs whose sum is 10
Write a Python program to print every pair of elements from a list whose sum is 10.
Input
[2, 8, 5, 3, 7, 5, 1]
Output
[(2, 8), (5, 5), (3, 7)]
Approach
- Check every pair (i, j) with j after i so no pair is repeated.
Solution
numbers = [2, 8, 5, 3, 7, 5, 1]pairs = []for i in range(len(numbers)): for j in range(i + 1, len(numbers)): if numbers[i] + numbers[j] == 10: pairs.append((numbers[i], numbers[j]))print(pairs)Output
[(2, 8), (5, 5), (3, 7)]
Line by line
Line 4
Starting the inner loop at i + 1 avoids pairing an item with itself or counting a pair twice.
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