最长无重复子串长度

雨点打透心脏的1/2处 2024-03-08 08:18 97阅读 0赞

[*题目：给定一个字符串 s ，请你找出其中不含有重复字符的 最长子串 的长度。*][s _ _]

> 解题思路： 滑动窗口/双指针（计算长度） + hashMap（判重）

#### 代码： ####

class Solution {
        
        public int lengthOfLongestSubstring(String s) {
        
            int start = 0, max = 0;
            // 记录字符的下标
            HashMap<Character, Integer> map = new HashMap<>();
            //遍历
            for(int end = 0; end < s.length(); end++){
        
                // 获取end指针的字符
                char ch = s.charAt(end);
                // 判断ch字符是否在map中
                if(map.containsKey(ch)){
        
                    // 如果重复，则start指针跳跃到不重复的下一个位置
                    start = Math.max(map.get(ch) + 1, start);
                }
                // 计算当前不重复子串的最大长度
                max = Math.max(max, end-start+1);
                // 将end指针处的字符添加到map中
                map.put(ch, end);
            }
            return max;
        }
    }

#### 参考链接： ####

[https://leetcode.cn/problems/longest-substring-without-repeating-characters/solutions/227999/wu-zhong-fu-zi-fu-de-zui-chang-zi-chuan-by-leetc-2/comments/831272][https_leetcode.cn_problems_longest-substring-without-repeating-characters_solutions_227999_wu-zhong-fu-zi-fu-de-zui-chang-zi-chuan-by-leetc-2_comments_831272]

[s _ _]: https://leetcode.cn/problems/longest-substring-without-repeating-characters/description/
[https_leetcode.cn_problems_longest-substring-without-repeating-characters_solutions_227999_wu-zhong-fu-zi-fu-de-zui-chang-zi-chuan-by-leetc-2_comments_831272]: https://leetcode.cn/problems/longest-substring-without-repeating-characters/solutions/227999/wu-zhong-fu-zi-fu-de-zui-chang-zi-chuan-by-leetc-2/comments/831272