7. 查找众数及中位数

const readline = require('readline');
const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
});

rl.on('line', (input) => {
    const arr = input.split(" ").map(Number);
    const obj = {};
    let max = 1;
    for(let v of arr) {
        if (obj[v]) {
            obj[v] = obj[v] + 1;
        } else {
            obj[v] = 1;
        }
        max = Math.max(max, obj[v]);
    }
    let newArr = [];
    for(let i in obj) {
        if (obj[i] === max) {
            for(let j=0; j<max; j++) {
                newArr.push(i);
            }
        }
    }
    newArr.sort((a, b) => a-b);
    let ans;
    if (newArr.length % 2) {
        ans = (newArr.length + 1) / 2 - 1;
    } else {
        let index1 = newArr.length / 2;
        let index2 = newArr.length / 2 - 1;
        ans = (newArr[index1] + newArr[index2]) / 2;
    }
    console.log(ans);
});