题解 | #删除字符串中出现次数最少的字符#

const rl = require("readline").createInterface({ input: process.stdin });
var iter = rl[Symbol.asyncIterator]();
const readline = async () => (await iter.next()).value;

void async function () {
    while(line = await readline()){
        let string = line;
        const hash = {}
        // 创建哈希表
        for(let char of string) {
            hash[char] = (hash[char] || 0) + 1;
        }
        // console.log('创建哈希表', Object.entries(hash))
        // 找到最小值 
        const min = Math.min(...Object.values(hash));
        // console.log('最小值', Object.values(hash))
        // 找出重复次数最少的字符
        const deleteCharArr = Object.entries(hash).filter((charArr) => {
            return charArr[1] === min;
        })
        // console.log(deleteCharArr)
        // 删除重复次数最少的字符
        let sRegExp = '('
        deleteCharArr.forEach((charArr, index, array)=> {
            const char = charArr[0];
            sRegExp +=`${char}`;
            sRegExp += index < array.length-1 ? '|' : '';
        })
        sRegExp += ')'
        // console.log("sRegExp", sRegExp)
        const replaceRegExp = new RegExp(sRegExp, 'g')
        console.log(string.replace(replaceRegExp, ''))

    }
}()