Neil coding之路

規則

Given a string, find the length of the longest substring without repeating characters.

給定一個字串，找到不重複字元的最長字符串的長度

範例

Example 1:

Input: "abcabcbb"
Output: 3 
Explanation: The answer is "abc", with the length of 3. 

Example 2:

Input: "bbbbb"
Output: 1
Explanation: The answer is "b", with the length of 1.

Example 3:

Input: "pwwkew"
Output: 3
Explanation: 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.

解題思路

1.用新的字串存取不重複的字元

2.利用迴圈跑取輸入字串

3.回傳不重複字符串的最大長度

CODE

    var lengthOfLongestSubstring = function(s) {
        let arr="";
        let max=0;
        for(var i=0;i<s.length;i++)
        {
            let index=arr.indexOf(s[i]);
            arr+=s[i];
            if(index!=-1)
            {

               arr=arr.substring(index+1);
            }
            max=Math.max(max,arr.length);
        }

      

        return max;

    }