📜  在圆的圆周上由N个不同的点形成的四边形的数量

📅  最后修改于: 2021-06-25 12:38:19             🧑  作者: Mango

给定一个整数N ,该整数N表示圆的圆周上的点,则任务是找到使用这些点形成的四边形的数量。
例子:

方法:想法是使用置换和组合,通过圆的圆周上的N个点来找到可能的四边形的数量。可能的四边形数量为^{N}C_4
下面是上述方法的实现:

C++
// C++ implementation to find the
// number of quadrilaterals formed
// with N distinct points
#include
using namespace std;
 
// Function to find the factorial
// of the given number N
int fact(int n)
{
    int res = 1;
 
    // Loop to find the factorial
    // of the given number
    for(int i = 2; i < n + 1; i++)
       res = res * i;
        
    return res;
}
 
// Function to find the number of
// combinations in the N
int nCr(int n, int r)
{
    return (fact(n) / (fact(r) *
                       fact(n - r)));
}
 
// Driver Code
int main()
{
    int n = 5;
 
    // Function Call
    cout << (nCr(n, 4));
}
 
// This code is contributed by rock_cool


Java
// Java implementation to find the
// number of quadrilaterals formed
// with N distinct points
class GFG{
     
// Function to find the number of
// combinations in the N
static int nCr(int n, int r)
{
    return (fact(n) / (fact(r) *
                       fact(n - r)));
}
 
// Function to find the factorial
// of the given number N
static int fact(int n)
{
    int res = 1;
 
    // Loop to find the factorial
    // of the given number
    for(int i = 2; i < n + 1; i++)
        res = res * i;
    return res;
}
 
// Driver Code
public static void main(String[] args)
{
    int n = 5;
 
    // Function Call
    System.out.println(nCr(n, 4));
}
}
 
// This code is contributed by 29AjayKumar


Python3
# Python3 implementation to find the
# number of quadrilaterals formed
# with N distinct points
 
# Function to find the number of
# combinations in the N
def nCr(n, r):
    return (fact(n) / (fact(r)
                * fact(n - r)))
 
# Function to find the factorial
# of the given number N
def fact(n):
    res = 1
     
    # Loop to find the factorial
    # of the given number
    for i in range(2, n + 1):
        res = res * i    
    return res
 
# Driver Code
if __name__ == "__main__":
    n = 5
     
    # Function Call
    print(int(nCr(n, 4)))


C#
// C# implementation to find the
// number of quadrilaterals formed
// with N distinct points
using System;
class GFG{
     
// Function to find the number of
// combinations in the N
static int nCr(int n, int r)
{
    return (fact(n) / (fact(r) *
                       fact(n - r)));
}
 
// Function to find the factorial
// of the given number N
static int fact(int n)
{
    int res = 1;
 
    // Loop to find the factorial
    // of the given number
    for(int i = 2; i < n + 1; i++)
        res = res * i;
    return res;
}
 
// Driver Code
public static void Main(String[] args)
{
    int n = 5;
 
    // Function Call
    Console.Write(nCr(n, 4));
}
}
 
// This code is contributed by shivanisinghss2110


Javascript


输出:
5