CF27E Number With The Given Amount Of Divisors

https://www.luogu.com.cn/record/81585090

Luogu/CF27E/CF27E.cpp

@@ -0,0 +1,36 @@
+#include <iostream>
+#include <limits>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int primes[] = {2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53};
+
+int n;
+long long ans = std::numeric_limits<long long>::max();
+
+void dfs(long long now, int id, int max, int cnt) {
+    if (cnt > n || now <= 0 || now > ans || id > 15) return;
+    if (cnt == n) {
+        ans = now;
+        return;
+    }
+
+    for (int i = 1; i <= max; i++) {
+        dfs(now *= primes[id], id + 1, i, cnt * (i + 1));
+    }
+}
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n;
+
+    dfs(1, 0, 64, 1);
+
+    cout << ans << endl;
+
+    return 0;
+}