在给定方程中找到X和Y的值

给定两个数字$A$和$B$ 。在方程中找到X和Y的值。

1. A = X + Y
2. B = X或Y

任务是使X尽可能最小。如果找不到X和Y的有效值，则打印-1。
例子：

Input : A = 12, B = 8
Output : X = 2, Y = 10

Input : A = 12, B = 9
Output : -1

让我们看一下X中的某个位等于1。如果Y中的各个位等于0，则可以交换这两个位，从而减少X并增加Y，而无需更改它们的和和Xor。我们可以得出结论，如果X中的某个位等于1，则Y中的相应位也等于1。因此，Y = X +B。考虑到X + Y = X + X + B = A，则1可以获得以下公式来查找X和Y：

• X =(A – B)/ 2
• Y = X + B =(A + B)/ 2

还应该注意的是，如果A 或A和B的奇偶校验不同，则答案不存在，输出为-1。如果X和(A – X)不等于X，则答案也为-1。
下面是上述方法的实现：

C++

// CPP program to find the values of
// X and Y using the given equations
 
#include 
using namespace std;
 
// Function to find the
// values of X and Y
void findValues(int a, int b)
{
    // base condition
    if ((a - b) % 2 == 1) {
        cout << "-1";
        return;
    }
 
    // required answer
    cout << (a - b) / 2 << " " << (a + b) / 2;
}
 
// Driver Code
int main()
{
    int a = 12, b = 8;
 
    findValues(a, b);
 
    return 0;
}

Java

// Java program to find the values of
// X and Y using the given equations
import java.io.*;
 
class GFG
{
     
// Function to find the
// values of X and Y
static void findValues(int a, int b)
{
    // base condition
    if ((a - b) % 2 == 1)
    {
            System.out.println ("-1");
        return;
    }
 
    // required answer
    System.out.println (((a - b) / 2)+ " " +
                            ((a + b) / 2));
}
 
    // Driver Code
    public static void main (String[] args)
    {
        int a = 12, b = 8;
        findValues(a, b);
    }
}
 
// This code is contributed by ajit...

Python3

# Python3 program to find the values of
# X and Y using the given equations
 
# Function to find the values of X and Y
def findValues(a, b):
 
    # base condition
    if ((a - b) % 2 == 1):
        print("-1");
        return;
 
    # required answer
    print((a - b) // 2, (a + b) // 2);
 
# Driver Code
a = 12; b = 8;
 
findValues(a, b);
 
# This code is contributed
# by Akanksha Rai

C#

// C# program to find the values of
// X and Y using the given equations
using System;
 
class GFG
{
         
// Function to find the
// values of X and Y
static void findValues(int a, int b)
{
    // base condition
    if ((a - b) % 2 == 1)
    {
            Console.Write ("-1");
        return;
    }
 
    // required answer
    Console.WriteLine(((a - b) / 2)+ " " +
                        ((a + b) / 2));
}
 
// Driver Code
static public void Main ()
{
    int a = 12, b = 8;
    findValues(a, b);
}
}
 
// This code is contributed by @Tushil..

Javascript

 
// Javascript program to find the values of
// X and Y using the given equations
 
// Function to find the values
// of X and Y
function findValues(a, b)
{
    // base condition
    if ((a - b) % 2 == 1)
    {
        document.write( "-1");
        return;
    }
 
    // required answer
    document.write( (a - b) / 2+ " " +
        (a + b) / 2);
}
 
// Driver Code
let a = 12;
let b = 8;
findValues(a, b);
 
// This code is contributed
// by bobby
 

输出：

2 10