D1 - Divan and Kostomuksha (easy version)

https://codeforces.com/contest/1614/submission/137046622

CodeForces/1614/D1/D1.cpp

@@ -0,0 +1,37 @@
+#include <bits/stdc++.h>
+
+using std::cin;
+using std::cout;
+using std::endl;
+
+int n;
+long long a[100005], cnt[5000005], f[5000005], max, ans;
+
+int main() {
+    cin >> n;
+    for (int i = 1; i <= n; i++) {
+        cin >> a[i];
+        max = std::max(max, a[i]);
+    }
+    for (int i = 1; i <= n; i++) {
+        for (int j = 1; j * j <= a[i]; j++) {
+            if (a[i] % j == 0) {
+                cnt[j]++;
+                if (j * j != a[i]) {
+                    cnt[a[i] / j]++;
+                }
+            }
+        }
+    }
+    for (int i = 1; i <= max; i++) {
+        f[i] = cnt[i] * i;
+    }
+    for (int i = max; i > 0; i--) {
+        for (int j = i << 1; j <= max; j += i) {
+            f[i] = std::max(f[i], f[j] + (cnt[i] - cnt[j]) * i);
+        }
+        ans = std::max(ans, f[i]);
+    }
+    cout << ans << endl;
+    return 0;
+}