给定一个平面中的n个点,并且共线的点不超过两个,则任务是计算给定平面中三角形的数量。
例子:
Input : n = 3
Output : 1
Input : n = 4
Output : 4
假设一个平面中有n个点,并且没有三个或更多点是共线的,则给定平面中的三角形数由下式给出:
C++
// C++ program to find the number of
// triangles in a plane if no more
// then two points are collinear.
#include
using namespace std;
// Function to find number of triangles
// in a plane.
int countNumberOfTriangles(int n)
{
// Formula to find number of triangles
// nC3 = n * (n - 1) * (n - 2) / 6
return n * (n - 1) * (n - 2) / 6;
}
// Driver code
int main()
{
int n = 4;
cout << countNumberOfTriangles(n);
return 0;
}
Java
// Java program to find the number of
// triangles in a plane if no more
// then two points are collinear.
import java.io.*;
class GFG {
// Function to find number of triangles
// in a plane.
static int countNumberOfTriangles(int n)
{
// Formula to find number of triangle
// nC3 = n * (n - 1) * (n - 2) / 6
return n * (n - 1) * (n - 2) / 6;
}
// Driver code
public static void main(String[] args)
{
int n = 4;
System.out.println(
countNumberOfTriangles(n));
}
}
Python3
# Python3 program to find
# the number of triangles
# in a plane if no more
# then two points are collinear.
# Function to find number
# of triangles in a plane.
def countNumberOfTriangles(n) :
# Formula to find
# number of triangles
# nC3 = n * (n - 1) *
# (n - 2) / 6
return (n * (n - 1) *
(n - 2) // 6)
# Driver Code
if __name__ == '__main__' :
n = 4
print(countNumberOfTriangles(n))
# This code is contributed
# by ajit
C#
// C# program to find the
// number of triangles in
// a plane if no more then
// two points are collinear.
using System;
class GFG
{
// Function to find number
// of triangles in a plane.
static int countNumberOfTriangles(int n)
{
// Formula to find number
// of triangle
// nC3 = n * (n - 1) *
// (n - 2) / 6
return n * (n - 1) *
(n - 2) / 6;
}
// Driver code
public static void Main()
{
int n = 4;
Console.WriteLine(
countNumberOfTriangles(n));
}
}
// This code is contributed by anuj_67.
PHP
Javascript
输出:
4