Python
# Program to check if any pair in list sums to target
numbers = list(map(int, input("Enter integers separated by space: ").split()))
target = int(input("Enter target sum: "))
seen = set()
found = False
for x in numbers:
if target - x in seen:
found = True
break
seen.add(x)
if found:
print("Found a pair with the given sum.")
else:
print("No pair with the given sum found.")Output
Enter integers separated by space: 1 2 3 4 Enter target sum: 5 Found a pair with the given sum.
We use a set to track seen numbers and check for the complement (target - x) in O(1) average time.