1. 排序贪心 易得,相邻元素尽可能相邻结果最优。O(nlong) #include <iostream> #include <bits/stdc++.h> using namespace std; int main() { int n; cin >> n; typedef long long ll; vector<int> a(n); for (int i = 0; i < n; i++) { cin >> a[i]; } sort(a.begin(), a.end()); ll res = 0; for (int i = 0...