From 1aee9acbc968230158c7b77246d5fe3f35b9749c Mon Sep 17 00:00:00 2001
From: Baoshuo Ren <i@baoshuo.ren>
Date: Thu, 10 Feb 2022 01:31:54 +0800
Subject: [PATCH] =?UTF-8?q?#181.=20Alice&=E6=97=B6=E9=97=B4=E9=9A=A7?=
 =?UTF-8?q?=E9=81=93?=
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https://sjzezoj.com/submission/48560
---
 S2OJ/181/181.cpp | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)
 create mode 100644 S2OJ/181/181.cpp

diff --git a/S2OJ/181/181.cpp b/S2OJ/181/181.cpp
new file mode 100644
index 00000000..9626e4e1
--- /dev/null
+++ b/S2OJ/181/181.cpp
@@ -0,0 +1,27 @@
+#include <algorithm>
+#include <iostream>
+
+using std::cin;
+using std::cout;
+#define endl '\n'
+
+const int N = 200005;
+
+int n, a[N], ans;
+
+int main() {
+    cin >> n;
+    for (int i = 1; i <= n; i++) {
+        cin >> a[i];
+    }
+    std::sort(a + 1, a + 1 + n);
+    n = std::unique(a + 1, a + 1 + n) - a - 1;
+    a[n + 1] = std::numeric_limits<int>::max();
+    for (int i = 1; i <= n; i++) {
+        for (int j = 2; (j - 1) * a[i] <= a[n]; j++) {
+            ans = std::max(ans, *(std::lower_bound(a + 1, a + 1 + n + 1, j * a[i]) - 1) % a[i]);
+        }
+    }
+    cout << ans << endl;
+    return 0;
+}