Overview

This problem asks you to find the length of the longest contiguous subarray where every tree’s sweetness falls within \([L, R]\).

Analysis

To satisfy the condition “all \(T_i\) in the interval satisfy \(L \le T_i \le R\)”, even a single out-of-range value makes the entire interval invalid.
In other words, we can rephrase the problem as:

• Find the maximum length of a consecutive run of elements satisfying \(L \le T_i \le R\).

If we naively try all intervals \([l,r]\), there are \(O(N^2)\) of them, and including the cost of checking each interval makes it even heavier. Since \(N \le 2 \times 10^5\), an \(O(N^2)\) approach will certainly not be fast enough (TLE).

Instead, we can efficiently find the maximum length by scanning from left to right once, keeping track of “how far the current consecutive valid run extends.”

Example: For \(T = [3, 5, 2, 4, 6]\), \(L=3\), \(R=5\)
Whether each element satisfies the condition: [○, ○, ×, ○, ×], so the longest consecutive run of ○ has length 2 (the first 3, 5).

Algorithm

1. Let variable cur be “the current consecutive length satisfying the condition,” and best be “its maximum value.”
2. Scan the array from left to right.
   • If \(L \le x \le R\), then cur += 1 (the consecutive run extends)
   • Otherwise, cur = 0 (the consecutive run is broken, so reset)
3. At each step, update best = max(best, cur).
4. The final best is the answer (if no interval satisfies the condition, it naturally remains 0).

This method simply counts the length of each consecutive block of elements satisfying the condition and takes the maximum.

Complexity

• Time complexity: \(O(N)\) (a single scan)
• Space complexity: \(O(1)\) (only a constant number of variables besides the input array)

Implementation Notes

• The range check can be written concisely as L <= x <= R (Python’s comparison chaining).

• When an out-of-range value is encountered, “no interval containing that position is valid,” so the consecutive length cur must be reset to 0.

• Since the input can be large, reading it all at once with sys.stdin.buffer.read() is faster and safer.

  Source Code

import sys

def main():
    data = list(map(int, sys.stdin.buffer.read().split()))
    if not data:
        return
    N, L, R = data[0], data[1], data[2]
    T = data[3:3+N]

    best = 0
    cur = 0
    for x in T:
        if L <= x <= R:
            cur += 1
            if cur > best:
                best = cur
        else:
            cur = 0
    print(best)

if __name__ == "__main__":
    main()

This editorial was generated by gpt-5.2-high.