力扣 3. 无重复字符的最长子串 JavaScript

古城微笑少年丶 2022-11-07 04:13 122阅读 0赞

代码如下

/**
     * @param {string} s
     * @return {number}
     * 
     * 本解法的解题思路 
     * 假设有abacd
     * abacd 第一个无重复子串 ab
     * bacd  第一个无重复子串 bacd
     * acd   第一个无重复子串 acd
     * cd    第一个无重复字串 cd
     * d     第一个无重复子串 d
     * 所以最长bacd 4
     */
    var lengthOfLongestSubstring = function (s) {
        
        let maxLongStr = '';
        for (let index = 0; index < s.length; index++) {
        
            let subStr = s.substr(index, s.length);
            let tempSubStr = getFirstSubStr(subStr); // 取字串
            if (maxLongStr.length < tempSubStr.length) {
         // 字串长度比较
                maxLongStr = tempSubStr;
            }
        }
    
        console.log("one of longest str is : '" + maxLongStr + "', length is " + maxLongStr.length);
        return maxLongStr.length;
    };
    
    // 只取出子字符串中第一个无重复的字串
    var getFirstSubStr = function (s) {
        
        let tempStr = '';
        for (const item of s) {
        
            if (tempStr.indexOf(item) === -1) {
        
                tempStr += item;
            } else {
        
                return tempStr;
            }
        }
        return tempStr;
    }
    
    lengthOfLongestSubstring("abcabcbb");
    lengthOfLongestSubstring("bbbbb");
    lengthOfLongestSubstring("pwwkew");
    lengthOfLongestSubstring("");
    lengthOfLongestSubstring("dvdf");
    lengthOfLongestSubstring("sajakf4hrwj");
    lengthOfLongestSubstring("abacd");
    
    // output
    
    /*
    one of longest str is : 'abc', length is 3
    one of longest str is : 'b', length is 1
    one of longest str is : 'wke', length is 3
    one of longest str is : '', length is 0
    one of longest str is : 'vdf', length is 3
    one of longest str is : 'jakf4hrw', length is 8
    */

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[https://github.com/lesliefish/leetcode-js][https_github.com_lesliefish_leetcode-js]

[https_github.com_lesliefish_leetcode-js]: https://github.com/lesliefish/leetcode-js