Sliding Window· 25 min

Maximum Number of Vowels in a Substring of Given Length

LeetCode #1456 · Medium · Interactive step-by-step visualization

Setup

Example inputs = "abciiidef", k = 3
Step 1 / 28

Current step

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Build the first fixed window. Exactly 3 contiguous items belong to each candidate. Vowel count starts at 1.

Step log

s = "abciiidef", k = 3

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Current dotted windowSaved best range

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best

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maximum-number-of-vowels-in-a-substring-of-given-length.java
1public int maxVowels(String s, int k) {
2    int count = 0;
3    for (int i = 0; i < k; i++) if (isVowel(s.charAt(i))) count++;
4    int best = count;
5    for (int right = k; right < s.length(); right++) {
6        if (isVowel(s.charAt(right))) count++;
7        if (isVowel(s.charAt(right - k))) count--;
8        best = Math.max(best, count);
9    }
10    return best;
11}
● Java
Time
O(n)
Space
O(1)
Pattern
sliding window
Frames
28
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