#1487. 【2022.7.27】商店购物（sum）

https://sjzezoj.com/submission/54214

S2OJ/1487/1487.cpp

@@ -0,0 +1,36 @@
+#include <iostream>
+#include <algorithm>
+#include <cmath>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 1e5 + 5;
+
+int n, a[N];
+long long lst, sum, ans;
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n;
+
+    for (int i = 1; i <= n; i++) {
+        cin >> a[i];
+    }
+
+    std::sort(a + 1, a + 1 + n);
+
+    for (int i = 0; i <= n; i++) {
+        sum += a[i];
+        while (a[i] == a[i + 1]) sum += a[++i];
+        ans += sum - std::max(lst, (static_cast<long long>(a[i]) + 1 >> 1) - 1);
+        lst = sum;
+    }
+
+    cout << ans << endl;
+
+    return 0;
+}