From 8df881adf092b0cfd69bd5ebaeb095bbe56a181e Mon Sep 17 00:00:00 2001
From: Baoshuo <i@baoshuo.ren>
Date: Thu, 6 Oct 2022 08:35:39 +0800
Subject: [PATCH] =?UTF-8?q?P1792=20[=E5=9B=BD=E5=AE=B6=E9=9B=86=E8=AE=AD?=
 =?UTF-8?q?=E9=98=9F]=E7=A7=8D=E6=A0=91?=
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https://www.luogu.com.cn/record/88801338
---
 Luogu/P1792/P1792.cpp | 58 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 Luogu/P1792/P1792.cpp

diff --git a/Luogu/P1792/P1792.cpp b/Luogu/P1792/P1792.cpp
new file mode 100644
index 00000000..9f39cfe2
--- /dev/null
+++ b/Luogu/P1792/P1792.cpp
@@ -0,0 +1,58 @@
+#include <iostream>
+#include <functional>
+#include <queue>
+#include <utility>
+#include <vector>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 2e5 + 5;
+
+int n, m, a[N], pre[N], suf[N], ans;
+bool vis[N];
+std::priority_queue<std::pair<int, int>> q;
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n >> m;
+
+    if (n / 2 < m) {
+        cout << "Error!" << endl;
+
+        exit(0);
+    }
+
+    for (int i = 1; i <= n; i++) {
+        cin >> a[i];
+
+        pre[i] = i - 1 ? i - 1 : n;
+        suf[i] = i == n ? 1 : i + 1;
+
+        q.emplace(a[i], i);
+    }
+
+    for (int i = 1; i <= m; i++) {
+        while (!q.empty() && vis[q.top().second]) q.pop();
+
+        auto o = q.top();
+        q.pop();
+
+        vis[pre[o.second]] = vis[suf[o.second]] = true;
+        a[o.second] = a[pre[o.second]] + a[suf[o.second]] - a[o.second];
+        q.emplace(a[o.second], o.second);
+        ans += o.first;
+
+        pre[o.second] = pre[pre[o.second]];
+        suf[o.second] = suf[suf[o.second]];
+        pre[suf[o.second]] = o.second;
+        suf[pre[o.second]] = o.second;
+    }
+
+    cout << ans << endl;
+
+    return 0;
+}