description: CQXYM wants to create a connected undirected graph with n nodes and m edges, and the diameter of the graph must be strictly less than k-1. Also, CQXYM doesn't want a graph that contains self-loops or multiple edges (i.e. each edge connects two different vertices and between each pair of vertices there is at most one edge).
  
  The diameter of a graph is the maximum distance between any two nodes.
  
  The distance between two nodes is the minimum number of the edges on the path which endpoints are the two nodes.
  
  CQXYM wonders whether it is possible to create such a graph.
  
  Input
  
  The input consists of multiple test cases. 
  
  The first line contains an integer t (1 ≤ t ≤ 10^5) — the number of test cases. The description of the test cases follows.
  
  Only one line of each test case contains three integers n(1 ≤ n ≤ 10^9), m, k (0 ≤ m,k ≤ 10^9).
  
  Output
  
  For each test case, print YES if it is possible to create the graph, or print NO if it is impossible. You can print each letter in any case (upper or lower).
  
  Example
  
  Input
  
  
  5
  1 0 3
  4 5 3
  4 6 3
  5 4 1
  2 1 1
  
  
  Output
  
  
  YES
  NO
  YES
  NO
  NO
  
  Note
  
  In the first test case, the graph's diameter equal to 0.
  
  In the second test case, the graph's diameter can only be 2.
  
  In the third test case, the graph's diameter can only be 1.
solution: import java.util.*;
  import java.io.*;
  
  public class B {
  
      public void prayGod() throws IOException {
          int t = nextInt();
          while (t-- > 0) {
              long n = nextLong();
              long m = nextLong();
              long k = nextLong();
  
              if (m < n - 1 || m > n * (n - 1) / 2) {
                  printVerdict(false);
                  continue;
              }
  
              if (n == 1) {
                  printVerdict(k >= 2);
                  continue;
              }
  
              int lowBound = 3;
              if (m < n * (n - 1) / 2)
                  lowBound++;
  
              printVerdict(k >= lowBound);
  
          }
      }
  
      public void printVerdict(boolean verdict) {
          if (verdict)
              out.println(VERDICT_YES);
          else
              out.println(VERDICT_NO);
      }
  
      static final String VERDICT_YES = "YES";
      static final String VERDICT_NO = "NO";
      static final boolean RUN_TIMING = true;
      static final boolean AUTOFLUSH = false;
      static final boolean FILE_INPUT = false;
      static final boolean FILE_OUTPUT = false;
  
      static int iinf = 0x3f3f3f3f;
      static long inf = (long) 1e18 + 10;
      static long mod = (long) 1e9 + 7;
  
      static char[] inputBuffer = new char[1 << 20];
      static PushbackReader in = new PushbackReader(new BufferedReader(new InputStreamReader(System.in)), 1 << 20);
      static PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)), AUTOFLUSH);
  
      // int data-type
      public int nextInt() throws IOException {
          return Integer.parseInt(next());
      }
  
      public int[] nextIntArray(int n) throws IOException {
          int[] arr = new int[n];
          for (int i = 0; i < n; i++)
              arr[i] = nextInt();
          return arr;
      }
  
      public void sort(int[] a) {
          shuffle(a);
          Arrays.sort(a);
      }
  
      public static void printArray(int[] arr) {
          for (int i = 0; i < arr.length; i++)
              out.print(arr[i] + " ");
          out.println();
      }
  
      // long data-type
      public long nextLong() throws IOException {
          return Long.parseLong(next());
      }
  
      public long[] nextLongArray(int n) throws IOException {
          long[] arr = new long[n];
          for (int i = 0; i < n; i++)
              arr[i] = nextLong();
          return arr;
      }
  
      public static void printArray(long[] arr) {
          for (int i = 0; i < arr.length; i++)
              out.print(arr[i] + " ");
          out.println();
      }
  
      public void sort(long[] a) {
          shuffle(a);
          Arrays.sort(a);
      }
  
      // double data-type
      public double nextDouble() throws IOException {
          return Double.parseDouble(next());
      }
  
      public double[] nextDoubleArray(int n) throws IOException {
          double[] arr = new double[n];
          for (int i = 0; i < n; i++)
              arr[i] = nextDouble();
          return arr;
      }
  
      public static void printArray(double[] arr) {
          for (int i = 0; i < arr.length; i++)
              out.print(arr[i] + " ");
          out.println();
      }
  
      // Generic type
      public <T> void sort(T[] a) {
          shuffle(a);
          Arrays.sort(a);
      }
  
      public static <T> void printArray(T[] arr) {
          for (int i = 0; i < arr.length; i++)
              out.print(arr[i] + " ");
          out.println();
      }
  
      public String next() throws IOException {
          int len = 0;
          int c;
          do {
              c = in.read();
          } while (Character.isWhitespace(c) && c != -1);
          if (c == -1) {
              throw new NoSuchElementException("Reached EOF");
          }
          do {
              inputBuffer[len] = (char) c;
              len++;
              c = in.read();
          } while (!Character.isWhitespace(c) && c != -1);
          while (c != '\n' && Character.isWhitespace(c) && c != -1) {
              c = in.read();
          }
          if (c != -1 && c != '\n') {
              in.unread(c);
          }
          return new String(inputBuffer, 0, len);
      }
  
      public String nextLine() throws IOException {
          int len = 0;
          int c;
          while ((c = in.read()) != '\n' && c != -1) {
              if (c == '\r') {
                  continue;
              }
              inputBuffer[len] = (char) c;
              len++;
          }
          return new String(inputBuffer, 0, len);
      }
  
      public boolean hasNext() throws IOException {
          String line = nextLine();
          if (line.isEmpty()) {
              return false;
          }
          in.unread('\n');
          in.unread(line.toCharArray());
          return true;
      }
  
      public void shuffle(int[] arr) {
          int n = arr.length;
          for (int i = 0; i < n; i++) {
              int j = (int) (Math.random() * (n - i));
              int temp = arr[i];
              arr[i] = arr[j];
              arr[j] = temp;
          }
      }
  
      public void shuffle(long[] arr) {
          int n = arr.length;
          for (int i = 0; i < n; i++) {
              int j = (int) (Math.random() * (n - i));
              long temp = arr[i];
              arr[i] = arr[j];
              arr[j] = temp;
          }
      }
  
      public void shuffle(Object[] arr) {
          int n = arr.length;
          for (int i = 0; i < n; i++) {
              int j = (int) (Math.random() * (n - i));
              Object temp = arr[i];
              arr[i] = arr[j];
              arr[j] = temp;
          }
      }
  
      public static void main(String[] args) throws IOException {
          if (FILE_INPUT)
              in = new PushbackReader(new BufferedReader(new FileReader(new File("output.txt"))), 1 << 20);
          if (FILE_OUTPUT)
              out = new PrintWriter(new FileWriter(new File("output.txt")));
  
          long time = 0;
          time -= System.nanoTime();
          new B().prayGod();
          time += System.nanoTime();
  
          if (RUN_TIMING)
              System.err.printf("%.3f ms%n", time / 1000000.0);
  
          out.flush();
          in.close();
      }
  }