35. 最大N个数与最小N个数的和

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

rl.on('line', function(input) {
    const inputArr = input.split(' ').map(Number);
    const size = inputArr[0];
    rl.on('line', (line) => {
        const nums = line.split(' ').map(Number);
        rl.on('line', (nLine) => {
            const n = Number(nLine);
            console.log(getN(size, nums, n));
        })
    })
})

function getN(size, nums, n) {
    if (nums.length < n*2) {
        return -1;
    }
    const distinctNums = [...new Set(nums)].sort((a, b) => a - b);
    let left = 0;
    let right = distinctNums.length - 1;
    let sum = 0;
    while(n > 0) {
        sum += distinctNums[left] + distinctNums[right];
        left++;
        right--;
        n--;
    }
    return sum;
}