242. 有效的字母异位词

leetcode

解法一：使用数组

function isAnagramArray(s: string, t: string): boolean {
  if (s.length !== t.length) {
    return false;
  }

  const LOWERCASE_A_CODE = "a".charCodeAt(0); // 97
  const count = new Array(26).fill(0);

  for (let i = 0; i < s.length; i++) {
    count[s.charCodeAt(i) - LOWERCASE_A_CODE]++;
    count[t.charCodeAt(i) - LOWERCASE_A_CODE]--;
  }

  return count.every((val) => val === 0);
}

// 测试
console.log(isAnagramArray("anagram", "nagaram")); // 输出: true
console.log(isAnagramArray("rat", "car")); // 输出: false

解法二：使用哈希表（对象）

function isAnagramObject(s: string, t: string): boolean {
  if (s.length !== t.length) {
    return false;
  }

  const charCount: { [key: string]: number } = {};

  for (const char of s) {
    charCount[char] = (charCount[char] || 0) + 1;
  }

  for (const char of t) {
    if (!charCount[char]) {
      return false;
    }
    charCount[char]--;
    if (charCount[char] < 0) {
      return false;
    }
  }

  return true;
}

// 测试
console.log(isAnagramObject("listen", "silent")); // 输出: true
console.log(isAnagramObject("hello", "world")); // 输出: false
console.log(isAnagramObject("aacc", "ccac")); // 输出: false

ts 简单解法

function isAnagram(s: string, t: string): boolean {
  let ss = s.split("").sort().join("");
  let ts = t.split("").sort().join("");
  return ss == ts;
}