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  1. #include <bits/stdc++.h>
  2. using namespace std;
  3. using ivec = vector<int>;
  4. const int mod = 1e9+7;
  5.  
  6. struct products {
  7. 	int maxScore = 0;
  8. 	inline int sum(const ivec &a, int u, int v) {
  9. 		int s = 0;
  10. 		while (u < v)
  11. 			if (s += a[u++], s >= mod)
  12. 				s -= mod;
  13. 		return s; }
  14.     inline void mac(const ivec &a, int i, int u, int v) {
  15.     	long long w = 1ll*i*sum(a,u,v);
  16.     	if (w %= mod, maxScore += w, maxScore >= mod)
  17.     		maxScore -= mod; }
  18.     inline products(ivec &a, int m) {
  19.         int n = a.size(), p = n/m, u = 0, v = m;
  20.         sort(a.begin(),a.end());  
  21.         for (int i = 1; i < p; ++i)
  22.         	mac(a,i,u,v), u = v, v += m;
  23.     	mac(a,p,u,n); } };
  24.  
  25. inline int maxScore(ivec &a, int m) { return products(a,m).maxScore; }
  26.  
  27. int main() {
  28.     int n, m; ivec a;
  29.     ios_base::sync_with_stdio(0), cin.tie(0), cin >> n >> m, a.resize(n);
  30.     for (auto &b: a)
  31.         cin >> b;
  32.     cout << maxScore(a,m); }
  33.  
Success #stdin #stdout 0s 4116KB
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https://ideone.com/RzghZd
Product Distribution
language:
C++14 (gcc 8.3)
created:
4 years ago
visibility:
secret

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