Given N number of vertices of a Graph. The task is to find the total number of edges possible in a complete graph of N vertices.
Complete Graph: A Complete Graph is a graph in which every pair of vertices is connected by an edge.
Examples:
Input : N = 3 Output : Edges = 3 Input : N = 5 Output : Edges = 10
The total number of possible edges in a complete graph of N vertices can be given as,
Total number of edges in a complete graph of N vertices = ( n * ( n – 1 ) ) / 2
Example 1: Below is a complete graph with N = 5 vertices.
The total number of edges in the above complete graph = 10 = (5)*(5-1)/2.
Implementation:
// C++ implementation to find the // number of edges in a complete graph #include <bits/stdc++.h> using namespace std;
// Function to find the total number of // edges in a complete graph with N vertices int totEdge( int n)
{ int result = 0;
result = (n * (n - 1)) / 2;
return result;
} // Driver Code int main()
{ int n = 6;
cout << totEdge(n);
return 0;
} |
// Java implementation to find the // number of edges in a complete graph class GFG {
// Function to find the total number of // edges in a complete graph with N vertices static int totEdge( int n)
{ int result = 0 ;
result = (n * (n - 1 )) / 2 ;
return result;
} // Driver Code
public static void main(String []args)
{
int n = 6 ;
System.out.println(totEdge(n));
}
} |
# Python 3 implementation to # find the number of edges # in a complete graph # Function to find the total # number of edges in a complete # graph with N vertices def totEdge(n) :
result = (n * (n - 1 )) / / 2
return result
# Driver Code if __name__ = = "__main__" :
n = 6
print (totEdge(n))
# This code is contributed # by ANKITRAI1 |
// C# implementation to find // the number of edges in a // complete graph using System;
class GFG
{ // Function to find the total // number of edges in a complete // graph with N vertices static int totEdge( int n)
{ int result = 0;
result = (n * (n - 1)) / 2;
return result;
} // Driver Code public static void Main()
{ int n = 6;
Console.Write(totEdge(n));
} } // This code is contributed // by ChitraNayal |
<?php // PHP implementation to find // the number of edges in a // complete graph // Function to find the total // number of edges in a complete // graph with N vertices function totEdge( $n )
{ $result = 0;
$result = ( $n * ( $n - 1)) / 2;
return $result ;
} // Driver Code $n = 6;
echo totEdge( $n );
// This code is contributed // by Shivi_Aggarwal ?> |
<script> // Javascript implementation to find the // number of edges in a complete graph // Function to find the total number of // edges in a complete graph with N vertices function totEdge(n)
{ var result = 0;
result = (n * (n - 1)) / 2;
return result;
} // Driver Code var n = 6;
document.write( totEdge(n)); </script> |
15
Complexity Analysis:
- Time Complexity: O(1)
- Auxiliary Space: O(1)