检查数字是否可以表示为两个平方的差

给定数字N ，任务是检查此数字是否可以表示为两个完美平方的差。

例子：

Input: N = 3 
Output: Yes 
Explanation: 
2² – 1¹ = 3

Input: N = 10 
Output: No 
 

方法：这个想法是所有的数字都可以表示为两个平方的差，除了当除以4时得出2的余数的数字。

让我们通过一些示例来形象地看待这一点：

N = 4 => 42 - 02
N = 6 => Can't be expressed as 6 % 4 = 2
N = 8 => 32 - 12
N = 10 => Can't be expressed as 10 % 4 = 2
N = 11 => 62 - 52
N = 12 => 42 - 22
and so on...

因此，想法是在给定数字除以4时简单地检查2的余数。

下面是上述方法的实现：

C++

// C++ program to check whether a number
// can be represented by the difference
// of two squares
 
#include 
using namespace std;
 
// Function to check whether a number
// can be represented by the difference
// of two squares
bool difSquare(int n)
{
    // Checking if n % 4 = 2 or not
    if (n % 4 != 2) {
        return true;
    }
 
    return false;
}
 
// Driver code
int main()
{
 
    int n = 45;
    if (difSquare(n)) {
        cout << "Yes\n";
    }
    else {
        cout << "No\n";
    }
    return 0;
}

Java

// Java program to check whether a number
// can be represented by the difference
// of two squares
import java.util.*;
 
class GFG{
 
// Function to check whether a number
// can be represented by the difference
// of two squares
static boolean difSquare(int n)
{
     
    // Checking if n % 4 = 2 or not
    if (n % 4 != 2)
    {
        return true;
    }
    return false;
}
 
// Driver code
public static void main(String[] args)
{
    int n = 45;
     
    if (difSquare(n))
    {
        System.out.print("Yes\n");
    }
    else
    {
        System.out.print("No\n");
    }
}
}
 
// This code is contributed by shivanisinghss2110

Python3

# Python3 program to check whether a number
# can be represented by the difference
# of two squares
 
# Function to check whether a number
# can be represented by the difference
# of two squares
def difSquare(n):
     
    # Checking if n % 4 = 2 or not
    if (n % 4 != 2):
        return True
    return False
 
# Driver code
if __name__ == '__main__':
     
    n = 45
     
    if (difSquare(n)):
        print("Yes")
    else:
        print("No")
 
# This code is contributed by mohit kumar 29

C#

// C# program to check whether a number
// can be represented by the difference
// of two squares
using System;
class GFG{
 
// Function to check whether a number
// can be represented by the difference
// of two squares
static bool difSquare(int n)
{
     
    // Checking if n % 4 = 2 or not
    if (n % 4 != 2)
    {
        return true;
    }
    return false;
}
 
// Driver code
public static void Main()
{
    int n = 45;
     
    if (difSquare(n))
    {
        Console.Write("Yes\n");
    }
    else
    {
        Console.Write("No\n");
    }
}
}
 
// This code is contributed by Nidhi_biet

Javascript

 
// Javascript program to check whether a number
// can be represented by the difference
// of two squares
 
// Function to check whether a number
// can be represented by the difference
// of two squares
function difSquare(n)
{
     
    // Checking if n % 4 = 2 or not
    if (n % 4 != 2)
    {
        return true;
    }
    return false;
}
 
// Driver code
var n = 45;
 
if (difSquare(n))
{
    document.write("Yes\n");
}
else
{
    document.write("No\n");
}
 
// This code is contributed by Rajput-Ji
 

输出：

Yes