Diet Plan Performance — Algorithm Visualization & Coding Challenge

🥗 Diet Plan Performance

A dieter tracks the number of calories consumed each day.
You are given an integer array calories, where calories[i] represents the calories consumed on the iᵗʰ day.

You are also given three integers:

• k → number of consecutive days to consider at a time
• lower → minimum healthy calorie limit
• upper → maximum healthy calorie limit

📊 Scoring Rules

For every contiguous group of k days:

1. Calculate the total calories for those k days.
2. Compare the total with the given limits:
   • If the total is less than lower, subtract 1 from the score.
   • If the total is greater than upper, add 1 to the score.
   • If the total lies between lower and upper (inclusive), the score does not change.

🎯 Goal

After checking all possible groups of k consecutive days, return the final score.

📐 Constraints

• 1 ≤ calories.length ≤ 10⁵
• 0 ≤ calories[i] ≤ 10⁴
• 1 ≤ k ≤ calories.length
• 0 ≤ lower ≤ upper ≤ 10⁹

🧠 Example 1

Input:

calories = [1, 2, 3, 4, 5]
k = 1
lower = 3
upper = 3

Explanation:

Since k = 1, each day is checked individually.

• Day 1 → 1 < 3 → score = -1
• Day 2 → 2 < 3 → score = -2
• Day 3 → 3 = 3 → score unchanged
• Day 4 → 4 > 3 → score = -1
• Day 5 → 5 > 3 → score = 0

Final Score: 0

🧠 Example 2

Input:

calories = [3, 2, 7, 5, 1]
k = 2
lower = 4
upper = 8

Step-by-step Explanation:

All possible subarrays of length k = 2:

• Days 1–2 → 3 + 2 = 5 → between 4 and 8 → score unchanged
• Days 2–3 → 2 + 7 = 9 → greater than 8 → score = +1
• Days 3–4 → 7 + 5 = 12 → greater than 8 → score = +2
• Days 4–5 → 5 + 1 = 6 → between 4 and 8 → score unchanged

Final Score: 2