Restock Alert
Easy · rating 1000 · Arrays, Implementation
A warehouse tracks items that need reordering. The first line contains n, the number of items. Each of the next n lines has two integers stock threshold. Print how many items have stock strictly below their threshold.
Constraints: 1 ≤ n ≤ 105
Editorial
Approach
For each item compare its stock to its threshold and count the ones that fall short. A running counter over the lines is all that's needed.
count = 0
for _ in range(n):
stock, threshold = map(int, input().split())
if stock < threshold:
count += 1
print(count)Watch the boundary
"Strictly below" means an item exactly at its threshold does not need restocking — use <, not ≤.
Complexity
Time: O(n). Space: O(1).
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