ARTS Week 41

示例 1:

输入: s = "cbaebabacd", p = "abc"
输出: [0,6]
解释:
起始索引等于 0 的子串是 "cba", 它是 "abc" 的异位词。
起始索引等于 6 的子串是 "bac", 它是 "abc" 的异位词。

const findAnagrams = function (s, p) {
    if (p.length > s.length) {
        return [];
    }

    let pCount = new Array(26).fill(0); 
    let sCount = new Array(26).fill(0);
    let result = [];

    for (let char of p) {
        pCount[char.charCodeAt(0) - 'a'.charCodeAt(0)] += 1;
    }
    for (let i = 0; i < p.length; i++) {
        sCount[s.charCodeAt(i) - 'a'.charCodeAt(0)] += 1;
    }

    if (isEqual(pCount, sCount)) {
        result.push(0);
    }
    for (let i = p.length; i < s.length; i++) {
        sCount[s.charCodeAt(i - p.length) - 'a'.charCodeAt(0)] -= 1;
        sCount[s.charCodeAt(i) - 'a'.charCodeAt(0)] += 1;
        if (isEqual(pCount, sCount)) {
            result.push(i - p.length + 1);
        }
    }

    function isEqual(count1, count2) {
        for (let i = 0; i < 26; i++) {
            if (count1[i] !== count2[i]) {
                return false;
            }
        }
        return true;
    }

    return result;

};