[Swift]LeetCode438. 找到字符串中所有字母异位词 | Find All Anagrams in a String
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Given a string s and a non-empty string p, find all the start indices of p's anagrams in s.
Strings consists of lowercase English letters only and the length of both strings s and pwill not be larger than 20,100.
The order of output does not matter.
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".
给定一个字符串 s 和一个非空字符串 p，找到 s 中所有是 p 的字母异位词的子串，返回这些子串的起始索引。
字符串只包含小写英文字母，并且字符串 s 和 p 的长度都不超过 20100。
说明：
- 字母异位词指字母相同，但排列不同的字符串。
- 不考虑答案输出的顺序。
示例 1:
输入: s: "cbaebabacd" p: "abc" 输出: [0, 6] 解释: 起始索引等于 0 的子串是 "cba", 它是 "abc" 的字母异位词。 起始索引等于 6 的子串是 "bac", 它是 "abc" 的字母异位词。
示例 2:
输入: s: "abab" p: "ab" 输出: [0, 1, 2] 解释: 起始索引等于 0 的子串是 "ab", 它是 "ab" 的字母异位词。 起始索引等于 1 的子串是 "ba", 它是 "ab" 的字母异位词。 起始索引等于 2 的子串是 "ab", 它是 "ab" 的字母异位词。
56ms
1 class Solution { 2 func findAnagrams(_ s: String, _ p: String) -> [Int] { 3 let sCount = s.utf8.count 4 let pCount = p.utf8.count 5 guard sCount >= pCount else { 6 return [] 7 } 8 var a = 97 9 var map = [Int](repeating: 0, count: 26) 10 p.utf8.forEach({ 11 map[Int($0) - a] += 1 12 }) 13 var sArray = Array(s.utf8) 14 var left = 0 15 var right = 0 16 var count = 0 17 var res = [Int]() 18 19 while right < sCount { 20 let rightIndex = Int(sArray[right]) - a 21 if map[rightIndex] > 0 { 22 map[rightIndex] -= 1 23 right += 1 24 count += 1 25 } else { 26 let leftIndex = Int(sArray[left]) - a 27 map[leftIndex] += 1 28 left += 1 29 count -= 1 30 } 31 if count == pCount { 32 res.append(left) 33 } 34 } 35 return res 36 } 37 }
80ms
1 class Solution { 2 func findAnagrams(_ s: String, _ p: String) -> [Int] { 3 let s = s.map { letterIndex($0) } 4 let p = p.map { letterIndex($0) } 5 6 var ref = Array(repeating: 0, count: 26) 7 for char in p { 8 ref[char] += 1 9 } 10 11 var result = [Int]() 12 var map = ref.map { _ in 0 } 13 for i in 0..<s.count { 14 map[s[i]] += 1 15 if i - p.count >= 0 { 16 map[s[i-p.count]] -= 1 17 } 18 19 if map == ref { 20 result.append(i - p.count + 1) 21 } 22 } 23 24 return result 25 } 26 27 func letterIndex(_ letter: Character) -> Int { 28 return Int(letter.unicodeScalars.first!.value) - Int(Unicode.Scalar("a").value) 29 } 30 }
84ms
1 class Solution { 2 func findAnagrams(_ s: String, _ p: String) -> [Int] { 3 if s.isEmpty { 4 return [] 5 } 6 var hash = Array(repeating: 0, count: 256) 7 for letter in p { 8 hash[letter.ascii] += 1 9 } 10 let s = [Character](s), p = [Character](p) 11 var left = 0, right = 0, count = p.count 12 var result = [Int]() 13 14 while right < s.count { 15 let index = s[right].ascii 16 if hash[index] >= 1 { 17 count -= 1 18 } 19 hash[index] -= 1 20 right += 1 21 22 if count == 0 { 23 result.append(left) 24 } 25 26 if right - left == p.count { 27 let leftIndex = s[left].ascii 28 if hash[leftIndex] >= 0 { 29 count += 1 30 } 31 hash[leftIndex] += 1 32 left += 1 33 } 34 } 35 return result 36 } 37 } 38 39 fileprivate extension Character { 40 var ascii: Int { 41 let utf8 = String(self).utf8 42 return Int(utf8[utf8.startIndex]) 43 } 44 }
100ms
1 class Solution { 2 func findAnagrams(_ s: String, _ p: String) -> [Int] { 3 if s.count < p.count { 4 return [] 5 } 6 7 var s = Array(s) 8 var i = 0, j = p.count - 1 9 10 var pOcc = Array(repeating: 0, count: 26) 11 var sOcc = Array(repeating: 0, count: 26) 12 13 for char in p { 14 pOcc[char.asciiValue - 97] += 1 15 } 16 17 for char in s.prefix(p.count) { 18 sOcc[char.asciiValue - 97] += 1 19 } 20 21 var result = [Int]() 22 while true { 23 if isValidAnagram(pOcc, sOcc) { 24 result.append(i) 25 } 26 27 i += 1 28 j += 1 29 if j >= s.count { break } 30 31 sOcc[s[i - 1].asciiValue - 97] -= 1 32 sOcc[s[j].asciiValue - 97] += 1 33 } 34 35 return result 36 } 37 38 func isValidAnagram(_ s: [Int], _ p: [Int]) -> Bool { 39 return s == p 40 } 41 } 42 43 extension Character { 44 var asciiValue: Int { 45 get { 46 let s = String(self).unicodeScalars 47 return Int(s[s.startIndex].value) 48 } 49 } 50 }
128ms
1 class Solution { 2 func findAnagrams(_ s: String, _ p: String) -> [Int] { 3 guard s.count > 0, s.count >= p.count else { 4 return [] 5 } 6 let sarr:[Character] = Array(s) 7 let parr:[Character] = Array(p) 8 var count = parr.count 9 var result = Array<Int>() 10 var map = Dictionary<Character, Int>() 11 12 for p in parr { 13 if map[p] == nil { 14 map[p] = 0 15 } 16 map[p]! += 1 17 } 18 19 var left = 0 20 var right = 0 21 22 while right < sarr.count { 23 if map[sarr[right]] == nil { 24 map[sarr[right]] = 0 25 } 26 27 if map[sarr[right]]! > 0 { 28 count -= 1 29 } 30 map[sarr[right]]! -= 1 31 right += 1 32 33 if count == 0 { 34 result.append(left) 35 } 36 37 if right - left == parr.count { 38 if map[sarr[left]] == nil { 39 map[sarr[left]] = 0 40 } 41 if map[sarr[left]]! >= 0 { 42 count += 1 43 } 44 map[sarr[left]]! += 1 45 left += 1 46 } 47 } 48 return result 49 } 50 }
132ms
1 class Solution { 2 3 let charToIntMap: [Character: Int] = [ 4 "a": 0, 5 "b": 1, 6 "c": 2, 7 "d": 3, 8 "e": 4, 9 "f": 5, 10 "g": 6, 11 "h": 7, 12 "i": 8, 13 "j": 9, 14 "k": 10, 15 "l": 11, 16 "m": 12, 17 "n": 13, 18 "o": 14, 19 "p": 15, 20 "q": 16, 21 "r": 17, 22 "s": 18, 23 "t": 19, 24 "u": 20, 25 "v": 21, 26 "x": 22, 27 "w": 23, 28 "y": 24, 29 "z": 25 30 ] 31 32 33 func findAnagrams(_ s: String, _ p: String) -> [Int] { 34 guard s.count >= p.count else { return [Int]() } 35 var i = 0 36 var j = 0 37 let sArr = Array(s) 38 let pArr = Array(p) 39 40 var pInt = Array<Int>(repeating: 0, count: 26) 41 var ans = [Int]() 42 43 for ch in pArr { 44 pInt[charToIntMap[ch]!] = pInt[charToIntMap[ch]!] + 1 45 } 46 var movingInt = Array<Int>(repeating: 0, count: 26) 47 while i < sArr.count && j < pArr.count { 48 let ch = sArr[i] 49 movingInt[charToIntMap[ch]!] = movingInt[charToIntMap[ch]!] + 1 50 i += 1 51 j += 1 52 } 53 if movingInt == pInt { 54 ans.append(0) 55 } 56 while i < sArr.count { 57 let ch = sArr[i] 58 let prevCh = sArr[i - j] 59 movingInt[charToIntMap[ch]!] = movingInt[charToIntMap[ch]!] + 1 60 movingInt[charToIntMap[prevCh]!] = movingInt[charToIntMap[prevCh]!] - 1 61 if movingInt == pInt { 62 ans.append(i - j + 1) 63 } 64 i += 1 65 } 66 return ans 67 } 68 }
164ms
1 class Solution { 2 func findAnagrams(_ s: String, _ p: String) -> [Int] { 3 guard s.count >= p.count else { return [] } 4 let sChars = Array(s.characters.map { String($0).uppercased() }) 5 let pChars = Array(p.characters.map { String($0).uppercased() }) 6 var result = [Int]() 7 var pCount = Array(repeating: 0, count: 26) 8 var windowCount = Array(repeating: 0, count: 26) 9 10 for i in 0..<pChars.count { 11 pCount[Int(UnicodeScalar(pChars[i])!.value) - Int(UnicodeScalar("A")!.value)] += 1 12 windowCount[Int(UnicodeScalar(sChars[i])!.value) - Int(UnicodeScalar("A")!.value)] += 1 13 } 14 15 for i in pChars.count..<sChars.count { 16 if compareArrays(pCount, windowCount) { result.append(i - pChars.count) } 17 18 windowCount[Int(UnicodeScalar(sChars[i - pChars.count])!.value) - Int(UnicodeScalar("A")!.value)] -= 1 19 windowCount[Int(UnicodeScalar(sChars[i])!.value) - Int(UnicodeScalar("A")!.value)] += 1 20 } 21 22 if compareArrays(pCount, windowCount) { result.append(sChars.count - pChars.count) } 23 24 return result 25 } 26 27 func compareArrays(_ a: [Int], _ b: [Int]) -> Bool { 28 guard a.count == b.count else { return false } 29 for i in 0..<a.count { 30 if a[i] != b[i] { return false } 31 } 32 return true 33 } 34 }
Runtime: 1776 ms
Memory Usage: 20.5 MB
1 class Solution { 2 func findAnagrams(_ s: String, _ p: String) -> [Int] { 3 if s.isEmpty || p.count > s.count {return []} 4 var res:[Int] = [Int]() 5 var m1:[Int] = [Int](repeating:0,count:256) 6 var m2:[Int] = [Int](repeating:0,count:256) 7 var arrS = Array(s).map{$0.ascii} 8 var arrP = Array(p).map{$0.ascii} 9 for i in 0..<p.count 10 { 11 m1[arrS[i]] += 1 12 m2[arrP[i]] += 1 13 } 14 if m1 == m2 15 { 16 res.append(0) 17 } 18 for i in p.count..<s.count 19 { 20 m1[arrS[i]] += 1 21 m1[arrS[i - p.count]] -= 1 22 if m1 == m2 23 { 24 res.append(i - p.count + 1) 25 } 26 } 27 return res 28 } 29 } 30 31 extension Character 32 { 33 //属性：ASCII整数值(定义小写为整数值) 34 var ascii: Int { 35 get { 36 let s = String(self).unicodeScalars 37 return Int(s[s.startIndex].value) 38 } 39 } 40 }
