第一题 #include<iostream> (5488)#include<vector> #include<algorithm> using namespace std; int main() { int size,n; int sum = 0; cin >> size; vector<int> arr(size); for (int i = 0; i < size; i++) { cin >> arr[i]; } sort(arr.begin(), arr.end()); arr.erase(unique(arr.begin(), arr.end()),arr.end()); cin >> n; if ((n - 1) >= (arr.size() - n)) cout << "-1" << endl; else { for (int i = 0; i < n ; i++) { sum += arr[i]; } for (int i = arr.size() - n ; i < arr.size() ; i++) { sum += arr[i]; } cout << sum << endl; } }