atcoder/abc186D

Author: xirc

atcoder/abc186/D/main.cpp

@@ -0,0 +1,34 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+using ll = int64_t;
+using ff = long double;
+
+int main() {
+    ios_base::sync_with_stdio(false);
+    cin.tie(0); cout.tie(0);
+
+    int N;
+    vector<ll> A;
+    
+    cin >> N;
+    A.assign(N, 0);
+    for (auto &a : A) cin >> a;
+
+    sort(A.begin(), A.end());
+    ll rhs = 0;
+    for (int i = 0; i < N; ++i) {
+        rhs += (N - i) * A[i];
+    }
+    ll lhs = 0;
+    for (int i = N - 1; i >= 0; --i) {
+        if (i + 1 < N) {
+            A[i] += A[i+1];
+        }
+        lhs += A[i];
+    }
+    ll ans = lhs - rhs;
+    cout << ans << endl;
+
+    return 0;
+}