Preview

Showing 10 of 32 steps

Next Warmer Day Alert

Medium

Find how many days until a warmer day arrives for each day, in O(n) with a monotonic stack

📊 Complexity

Type	Value
Best	O(n)
Average	O(n)
Worst	O(n)
Space	O(n)

🏷️ Tags

Monotonic StackStackArray

📋 Problem

Short-Sleeve Alert Service

You are the developer of the weather app 'Short Sleeves Tomorrow?'. Users most want to know "when will a day hotter than today come?". Given the forecast temperatures for the upcoming days, for each day produce an alert telling how many days later the **first warmer day** is. If no warmer day ever comes, report 0.

1/32

☀️Short-Sleeve Alert!

Forecast [23, 24, 22, 21, 25, 28, 26] Let's find how many days until the first warmer day for each day!

🔒

Short-Sleeve Alert Service

Description

Input

Array of daily forecast temperatures temps (Day 0, Day 1, ... from the front)

Output

Days until the first warmer day for each day (0 if none)

Constraints

•1 ≤ array length ≤ 100,000
•-50 ≤ temperature ≤ 50
•Temperatures are integers

Examples

Example 1

Input

temps = [23, 24, 22, 21, 25, 28, 26]

Output

[1, 3, 2, 1, 1, 0, 0]

Explanation

Day 0 (23°) → Day 1 (24°) = 1 day later Day 1 (24°) → Day 4 (25°) = 3 days later Day 2 (22°) → Day 4 (25°) = 2 days later Day 3 (21°) → Day 4 (25°) = 1 day later Day 4 (25°) → Day 5 (28°) = 1 day later Day 5 (28°) → No warmer day = 0 Day 6 (26°) → No warmer day = 0

Preview

Showing 10 of 32 steps

Next Warmer Day Alert

Medium

Next Warmer Day Alert

Find how many days until a warmer day arrives for each day, in O(n) with a monotonic stack

📊 Complexity

Type	Value
Best	O(n)
Average	O(n)
Worst	O(n)
Space	O(n)

🏷️ Tags

Monotonic StackStackArray

📋 Problem

Short-Sleeve Alert Service

1/32

☀️Short-Sleeve Alert!

Forecast [23, 24, 22, 21, 25, 28, 26] Let's find how many days until the first warmer day for each day!

🔒

Short-Sleeve Alert Service

Description

Input

Array of daily forecast temperatures temps (Day 0, Day 1, ... from the front)

Output

Days until the first warmer day for each day (0 if none)

Constraints

•1 ≤ array length ≤ 100,000
•-50 ≤ temperature ≤ 50
•Temperatures are integers

Examples

Example 1

Input

temps = [23, 24, 22, 21, 25, 28, 26]

Output

[1, 3, 2, 1, 1, 0, 0]

Explanation

Next Warmer Day Alert | AlgoNote