第一题： #include <iostream> #include <queue> #include <vector> using namespace std; int main() { int n; int i, j, k; int sum; int avg; vector<int> start; int count; bool flag; while (cin >> n) { sum = 0; for (i = 0; i < n; i++) { cin >> j; start.push_back(j); sum += j; } if (sum%n != 0) { cout << "-1" << endl; continue; } avg = sum/n; count = 0; flag = true; for (i = 0; i < n; i++) { if (start[i] > avg && (start[i]-avg)%2 != 0) { cout << "-1" << endl; flag = false; break; } if (start[i] < avg && (avg-start[i])%2 != 0) { cout << "-1" << endl; flag = false; break; } if (start[i] > avg) { count += (start[i]-avg)/2; } } if (flag) { cout << count << endl; } start.clear(); } return 0; }