题解 | #删除字符串中出现次数最少的字符#

const readline = require("readline");
const r1 = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
});
r1.on("line", function (line) {
    var str = line;
    // 化为数组并统计每个字母出现个数
    var list = line.split("").reduce(function (ever, now) {
        if (now in ever) {
            ever[now]++;
        } else {
            ever[now] = 1;
        }
        return ever;
    }, {});
    let min = 21;
    //求出最小值
    for (var i in list) {
        min = Math.min(min, list[i]);
    }
    for (var i in list) {
        if (min === list[i]) {
            let reg = new RegExp(i, "g");
            //删除字符串指定位置index
            str = str.replace(reg, "");
        }
    }
    console.log(str);
});