2506. 统计相似字符串对的数目

js代码：

/**
 * @param {string[]} words
 * @return {number}
 */
var similarPairs = function (words) {
    // 将字符串数组的每一项去重排序
    words = words.map(item => [...new Set(item)].sort().join(''))
    let res = 0
    
    for (let i = 0; i < words.length - 1; i++) {
        for (j = i + 1; j < words.length; j++) {
            if (words[i] == words[j]) res++
        }
    }
    return res
};