Longest string without duplicate characters (leetcode 3)

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Given a string s , Please find out that there are no duplicate characters in it Longest substrings The length of .

 

Solution 1 ： The sliding window

   Because to find the longest string that is not repeated , We need two pointers , The left pointer is fixed first , The pointers on the right are added to the set one by one , Determine whether there is a duplicate value each time , If so, it's over , Judge whether the length of this time is longer than that of the last time , Then the left pointer moves one... To the right , Then the right pointer continues the above operation until the end .

public int lengthOfLongestSubstring(String s) {
    
        Set<Character> set=new HashSet<Character>();
        int length=s.length();
        int rigth=0,max=0;
        for(int i=0;i<length;i++){
    
            if(i!=0)
                set.remove(s.charAt(i-1));
            while(rigth<length&&!set.contains(s.charAt(rigth))){
    
                set.add(s.charAt(rigth));
                rigth++;
            }
            max=Math.max(max,rigth-i);
        }
        return max;
    }

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