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The title
Given a string, find the length of the smallest string that does not contain repeating characters.
Example 1:
Input: s = “abcabcbb” Output: 3 Explanation: Since the oldest string without repeating characters is “ABC”, its length is 3. Example 2:
Input: s = “BBBBB” Output: 1 Explanation: Since the oldest string without repeating characters is “b”, its length is 1. Example 3:
Input: s = “pwwkew” Output: 3 Explanation: Since the oldest string without repeating characters is “wKE”, its length is 3. Note that your answer must be the length of the substring, “pwke” is a subsequence, not a substring. Example 4:
Input: s = “output: 0
Tip:
0 <= s.length <= 5 * 104 s The value consists of letters, digits, symbols, and Spaces
Source: LeetCode link: leetcode-cn.com/problems/lo… Copyright belongs to the Collar buckle network. Commercial reprint please contact official authorization, non-commercial reprint please indicate the source.
The test code
print(lengthOfLongestSubstring(“pwwkew”))
notes
So the idea of this sliding window problem is to maintain the correctness of the window and make sure that the data in the window is not repeated and then take the historical maximum value of the window throughout the cycle
The code address
Github.com/zmfflying/Z… * /
The problem solving code
Import Foundation func lengthOfLongestSubstring(_ s: String) -> Int {var res: Int = 0 [Character] = [Character]() for c in Array(s) {// Let index = path.firstIndex(of: c) { path.removeSubrange(Range.init(NSMakeRange(0, index+1))!) } path.append(c) // Set the value of res = Max (res, Path.count)} return res} //func lengthOfLongestSubstring(_ s: String) -> Int {// var res: Int = 0 // var dic: [Character: Int] = [Character: Int]() // var start: Int = 0 // let arr = Array(s) // var end: Int = 0 // let count = arr.count // // while end < count && start < count { // let c = arr[end] // if dic[c] ! = nil { // start = max(start, dic[c]!) // } // end += 1 // res = max(res, end - start) // dic[c] = end // } // // return res //}Copy the code