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438. Find All Anagrams in a String
Medium
Given two strings s and p, return an array of all the start indices of p’s anagrams in s. You may return the answer in any order.
An Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once.
Example 1:
Input: s = “cbaebabacd”, p = “abc”
Output: [0,6]
Explanation:
The substring with start index = 0 is "cba", which is an anagram of "abc".
The substring with start index = 6 is "bac", which is an anagram of "abc".
Example 2:
Input: s = “abab”, p = “ab”
Output: [0,1,2]
Explanation:
The substring with start index = 0 is "ab", which is an anagram of "ab".
The substring with start index = 1 is "ba", which is an anagram of "ab".
The substring with start index = 2 is "ab", which is an anagram of "ab".
Constraints:
1 <= s.length, p.length <= 3 * 104sandpconsist of lowercase English letters.
Solution
object Solution {
def findAnagrams(s: String, p: String): List[Int] = {
val map = new Array[Int](26)
for (i <- 0 until p.length) {
map(p.charAt(i) - 'a') += 1
}
var res = List[Int]()
var i = 0
var j = 0
while (i < s.length) {
val idx = s.charAt(i) - 'a'
map(idx) -= 1
if (i >= p.length) {
map(s.charAt(j) - 'a') += 1
j += 1
}
var finish = true
for (k <- 0 until 26) {
if (map(k) != 0) {
finish = false
}
}
if (i >= p.length - 1 && finish) {
res = j :: res
}
i += 1
}
res.reverse
}
}