B_Diameter_of_Graph.cpp

#include<bits/stdc++.h>
using namespace std;
#define ll long long int
#define pb push_back
#define mp make_pair
#define F first
#define S second
#define tr(it, a) for(auto it = a.begin(); it != a.end(); it++)
#define fo(i,n) for(ll i=0;i<n;i++)
#define all(v) v.begin(), v.end()
#define sortall(v) sort(all(v))
#define sortalld(v) sort(all(v),greater<ll>())
typedef pair<int, int>	pii;
typedef pair<ll, ll>	pl;
typedef vector<int> veci;
typedef vector<ll>  vecll;
typedef vector<pii>		vpii;
typedef vector<pl>		vpl;
const int mod = 1000000007;
int pow(int base, int exp) {base %= mod;int result = 1;while (exp > 0) {if (exp & 1) result = ((ll)result * base) % mod;base = ((ll)base * base) % mod;exp >>= 1;}return result;}
int T, P, Q, R, X, Y, U, V, N,M;
ll t, p, q, r, x, y, u, v, n, m,k;
int main() {
    ios_base::sync_with_stdio(0);
    cin>>t;
    while(t--)
    {
        cin >> n >> m >> k;
       if(n*(n-1)/2<m || n-1>m)
           cout << "NO" << endl;
           else if(k<=2 && n==2)
               cout << "NO" << endl;
               else if(k<=1 && n==1)
                   cout << "NO" << endl;
                   else if(n>=3&&(m<n*(n-1)/2&&k<=3||n-1>m||m>=n*(n-1)/2&&k<=2))
                       cout << "NO" << endl;
                       else
                           cout << "YES" << endl;
    }
}