From 810d9e19a315c0d1035c5b8e0c2ffa46ae98ba7f Mon Sep 17 00:00:00 2001
From: Ren Baoshuo <i@baoshuo.ren>
Date: Thu, 30 Sep 2021 20:34:51 +0800
Subject: [PATCH] B - Diameter of Graph

https://codeforces.com/contest/1581/submission/130353768
---
 CodeForces/1581/B/B.cpp | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 CodeForces/1581/B/B.cpp

diff --git a/CodeForces/1581/B/B.cpp b/CodeForces/1581/B/B.cpp
new file mode 100644
index 00000000..d199422f
--- /dev/null
+++ b/CodeForces/1581/B/B.cpp
@@ -0,0 +1,19 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+long long t, n, m, k;
+
+int main() {
+    cin >> t;
+    while (t--) {
+        cin >> n >> m >> k;
+        k -= 2;
+        if (n == 1) {
+            cout << (m == 0 && k >= 0 ? "YES" : "NO") << endl;
+        } else {
+            cout << ((m < n - 1 || n * (n - 1) < m * 2 || (n * (n - 1) == m * 2 && k < 1) || (n * (n - 1) > m * 2 && k < 2)) ? "NO" : "YES") << endl;
+        }
+    }
+    return 0;
+}