LeetCode3:无重复字符的最长字串

 

class Solution { public int lengthOfLongestSubstring(String s) { int n = s.length(); int ans = 0 ; int left = 0; int right = 0; Map<Character,Integer> map = new HashMap<>(); for(;right < n; right++){ char c = s.charAt(right); if(map.containsKey(c)){ left = Math.max(left,map.get(c)+1); } ans = Math.max(ans,right-left+1); map.put(c,right); } return ans; } }