题解 | #删除字符串中出现次数最少的字符#

const line = readline().split("");
const obj = {}; //出现第几次
const arrobj = []; //统计字符串出现第几次数组

//统计每个字符出现第几次
for (let item of line) {
  if (obj[item]) {
    obj[item]++;
  } else {
    obj[item] = 1;
  }
  arrobj.push(obj[item]);
}

var minChars = [];
var minCount = 20;
for (var x in obj) {
  if (minCount > obj[x]) {
    minCount = obj[x];
    minChars = [];
    minChars.push(x);
  } else if (minCount == obj[x]) {
    minChars.push(x);
  }
}

var res = line.join("");
for (var item of minChars) {
  var reg = new RegExp(item, "g");
  res = res.replace(reg, "");
}
console.log(res);