求逆序对数即可
function solution(line) {
var nums = line.split(",");
var res = 0;
for (let i = 0; i < nums.length - 1; i++) {
for (let j = i + 1; j < nums.length; j++) {
if (nums[i] > nums[j]) {
res += 1;
}
}
}
return res;
}