渣渣的救赎-LeetCode

leetcode java 实现3
Longest Substring Without Repeating Characters

public class Solution {    public int lengthOfLongestSubstring(String s) {        int i = 0, j = 0;        int maxlength = 0;        boolean exist[] = new boolean[256];        for(int k = 0;k< exist.length;k++){            exist[k]=false;        }        int n = s.length();        while(j<n){            if(exist[s.charAt(j)]){                maxlength = Math.max(j-i,maxlength);                while(s.charAt(i)!=s.charAt(j)){                     exist[s.charAt(i)]=false;                     i++;                }                i++;                j++;            }else{                exist[s.charAt(j)]= true;                j++;            }        }        maxlength = Math.max(n-i,maxlength);        return maxlength;    }}