From ffffd5fcd174a316c3d5680b112b9d6aba80d137 Mon Sep 17 00:00:00 2001
From: Ren Baoshuo <i@baoshuo.ren>
Date: Fri, 13 Aug 2021 18:38:30 +0800
Subject: [PATCH] =?UTF-8?q?48570=20=E3=80=90LGR-089=E3=80=91=E6=B4=9B?=
 =?UTF-8?q?=E8=B0=B7=208=20=E6=9C=88=E6=9C=88=E8=B5=9B=20II?=
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T166874: R55803919
---
 Luogu/contest/48570/T166874/T166874.cpp | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 Luogu/contest/48570/T166874/T166874.cpp

diff --git a/Luogu/contest/48570/T166874/T166874.cpp b/Luogu/contest/48570/T166874/T166874.cpp
new file mode 100644
index 00000000..2588cfdc
--- /dev/null
+++ b/Luogu/contest/48570/T166874/T166874.cpp
@@ -0,0 +1,17 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+const long long mod = 1e9 + 7;
+long long t, n, k, k1, k2;
+
+int main() {
+    cin >> t;
+    while (t--) {
+        cin >> n >> k;
+        k1 = k + 1 >> 1;
+        k2 = k >> 1;
+        cout << 1ll * (((((n * (n + 1)) / 2 % mod * k1 % mod) - (((k1 - 1) * k1) / 2 % mod) % mod) + ((((n - 1) * n) / 2 % mod * k2 % mod) - ((k2 - 1) * k2) / 2) % mod) % mod + mod) % mod << endl;
+    }
+    return 0;
+}