题解 | #最长不含重复字符的子字符串#

/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 * 
 * @param s string字符串 
 * @return int整型
 */
export function lengthOfLongestSubstring(s: string): number {
    // write code here
    const wordMap = new Map();
    let maxLen = 1,lastVal = 1;
    wordMap.set(s[0], 0);
    for(let i=1;i<s.length;i++) {
        const lastSimilarIdx = wordMap.get(s[i]);
        if(lastSimilarIdx === undefined) {
            lastVal += 1;
        } else {
            const dis = i - lastSimilarIdx;
            if(dis > lastVal) {
                lastVal += 1;
            } else {
                lastVal = dis;
            }
        }
        maxLen = Math.max(maxLen, lastVal);
        wordMap.set(s[i], i);
    }
    return maxLen;
}