杨新峰-20180810.md

【leetcode 算法题】

Longest Substring Without Repeating Characters，优化版

/**
 * 
 * Given a string, find the length of the longest substring without repeating characters.<br>
 * Examples:<br>
 * Given "abcabcbb", the answer is "abc", which the length is 3.<br>
 * Given "bbbbb", the answer is "b", with the length of 1.<br>
 * Given "pwwkew", the answer is "wke", with the length of 3. Note that the answer must be a substring, "pwke" is a subsequence and not a substring.<br>
 * 
 * @author yangxf
 *
 */
class Solution {
    public int lengthOfLongestSubstring(String s) {
        int ret = 0;
        Map<Character, Integer> map = new HashMap<Character, Integer>(); 
        for (int j = 0, i = 0; j < s.length(); j++) {
            if (map.containsKey(s.charAt(j))) {
                i = Math.max(map.get(s.charAt(j)), i);
            }
            ret = Math.max(ret, j - i + 1);
            map.put(s.charAt(j), j + 1);
        }
        return ret;
    }
}

【英文文章】

无重复字符的最长子串的解决方案

之前完成的ARTS中算法部分的Longest Substring Without Repeating Characters，发现执行效率很低，看了网站提供的解决方案，感觉还是有所启发和提升。

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【技术分享】

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