给定两个变量x和y，交换两个变量而不使用第三个变量。
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方法1（使用算术运算符）
这个想法是用两个给定的数字中的一个求和。然后可以使用求和和和的减法来交换这些数字。
C++
// C++ Program to swap two numbers without // using temporary variable #include <bits/stdc++.h> using namespace std; int main() { int x = 10, y = 5; // Code to swap 'x' and 'y' x = x + y; // x now becomes 15 y = x - y; // y becomes 10 x = x - y; // x becomes 5 cout << "After Swapping: x =" << x << ", y=" << y; } // This code is contributed by mohit kumar. |
C
#include <stdio.h> int main() { int x = 10, y = 5; // Code to swap 'x' and 'y' x = x + y; // x now becomes 15 y = x - y; // y becomes 10 x = x - y; // x becomes 5 printf ( "After Swapping: x = %d, y = %d" , x, y); return 0; } |
JAVA
// Java Program to swap two numbers without // using temporary variable import java.io.*; class Geeks { public static void main(String a[]) { int x = 10 ; int y = 5 ; x = x + y; y = x - y; x = x - y; System.out.println( "After swapping:" + " x = " + x + ", y = " + y); } } // This code is contributed by Mayank Tyagi |
蟒蛇3
x = 10 y = 5 # Code to swap 'x' and 'y' # x now becomes 15 x = x + y # y becomes 10 y = x - y # x becomes 5 x = x - y print ( "After Swapping: x =" , x, " y =" , y) # This code is contributed # by Sumit Sudhakar |
C#
// Program to swap two numbers without // using temporary variable using System; class GFG { public static void Main() { int x = 10; int y = 5; x = x + y; y = x - y; x = x - y; Console.WriteLine( "After swapping: x = " + x + ", y = " + y); } } // This code is contributed by Sam007 |
PHP
<?php // PHP Program to swap two // numbers without using // temporary variable $x = 10; $y = 5; // Code to swap 'x' and 'y' $x = $x + $y ; // x now becomes 15 $y = $x - $y ; // y becomes 10 $x = $x - $y ; // x becomes 5 echo "After Swapping: x = " , $x , ", " , "y = " , $y ; // This code is contributed by m_kit ?> |
Javascript
<script> // Javascript program to swap two // numbers without using temporary // variable let x = 10, y = 5; // Code to swap 'x' and 'y' // x now becomes 15 x = x + y; // y becomes 10 y = x - y; // x becomes 5 x = x - y; document.write( "After Swapping: x =" + x + ", y=" + y); // This code is contributed by mukesh07 </script> |
输出
After Swapping: x =5, y=10
乘法和除法也可用于交换。
C++
// C++ Program to swap two numbers // without using temporary variable #include <bits/stdc++.h> using namespace std; int main() { //NOTE - for this code to work in a generalised sense, y !- 0 to prevent zero division int x = 10, y = 5; // Code to swap 'x' and 'y' x = x * y; // x now becomes 50 y = x / y; // y becomes 10 x = x / y; // x becomes 5 cout << "After Swapping: x =" << x << ", y=" << y; } // This code is contributed by mohit kumar. |
C
// C Program to swap two numbers // without using temporary variable #include <stdio.h> int main() { int x = 10, y = 5; // Code to swap 'x' and 'y' x = x * y; // x now becomes 50 y = x / y; // y becomes 10 x = x / y; // x becomes 5 printf ( "After Swapping: x = %d, y = %d" , x, y); return 0; } |
JAVA
// Java Program to swap two numbers // without using temporary variable import java.io.*; class GFG { public static void main(String[] args) { int x = 10 ; int y = 5 ; // Code to swap 'x' and 'y' x = x * y; // x now becomes 50 y = x / y; // y becomes 10 x = x / y; // x becomes 5 System.out.println( "After swaping:" + " x = " + x + ", y = " + y); } } // This code is contributed by ajit |
蟒蛇3
# Python3 program to # swap two numbers # without using # temporary variable x = 10 y = 5 # code to swap # 'x' and 'y' # x now becomes 50 x = x * y # y becomes 10 y = x / / y; # x becomes 5 x = x / / y; print ( "After Swapping: x =" , x, " y =" , y); # This code is contributed # by @ajit |
C#
// C# Program to swap two // numbers without using // temporary variable using System; class GFG { static public void Main() { int x = 10; int y = 5; // Code to swap 'x' and 'y' x = x * y; // x now becomes 50 y = x / y; // y becomes 10 x = x / y; // x becomes 5 Console.WriteLine( "After swaping:" + " x = " + x + ", y = " + y); } } // This code is contributed by ajit. |
PHP
<?php // Driver code $x = 10; $y = 5; // Code to swap 'x' and 'y' $x = $x * $y ; // x now becomes 50 $y = $x / $y ; // y becomes 10 $x = $x / $y ; // x becomes 5 echo "After Swapping: x = " , $x , " " , "y = " , $y ; // This code is contributed by m_kit ?> |
Javascript
<script> // Javascript program to swap two numbers // without using temporary variable var x = 10; var y = 5; // Code to swap 'x' and 'y' x = x * y; // x now becomes 50 y = x / y; // y becomes 10 x = x / y; // x becomes 5 document.write( "After swaping:" + " x = " + x + ", y = " + y); // This code is contributed by shikhasingrajput </script> |
输出
After Swapping: x =5, y=10
方法2（使用按位异或） 按位异或运算符可用于交换两个变量。两个数字x和y的异或返回一个数字，无论x和y的位在哪里不同，该数字的所有位都为1。例如，10（二进制1010）和5（二进制0101）的异或为1111，7（0111）和5（0101）的异或为（0010）。
C++
// C++ code to swap using XOR #include <bits/stdc++.h> using namespace std; int main() { int x = 10, y = 5; // Code to swap 'x' (1010) and 'y' (0101) x = x ^ y; // x now becomes 15 (1111) y = x ^ y; // y becomes 10 (1010) x = x ^ y; // x becomes 5 (0101) cout << "After Swapping: x =" << x << ", y=" << y; return 0; } // This code is contributed by mohit kumar. |
C
// C code to swap using XOR #include <stdio.h> int main() { int x = 10, y = 5; // Code to swap 'x' (1010) and 'y' (0101) x = x ^ y; // x now becomes 15 (1111) y = x ^ y; // y becomes 10 (1010) x = x ^ y; // x becomes 5 (0101) printf ( "After Swapping: x = %d, y = %d" , x, y); return 0; } |
JAVA
// Java code to swap using XOR import java.io.*; public class GFG { public static void main(String a[]) { int x = 10 ; int y = 5 ; // Code to swap 'x' (1010) and 'y' (0101) x = x ^ y; // x now becomes 15 (1111) y = x ^ y; // y becomes 10 (1010) x = x ^ y; // x becomes 5 (0101) System.out.println( "After swap: x = " + x + ", y = " + y); } } // This code is contributed by Mayank Tyagi |
蟒蛇3
# Python3 code to swap using XOR x = 10 y = 5 # Code to swap 'x' and 'y' x = x ^ y; # x now becomes 15 (1111) y = x ^ y; # y becomes 10 (1010) x = x ^ y; # x becomes 5 (0101) print ( "After Swapping: x = " , x, " y =" , y) # This code is contributed by # Sumit Sudhakar |
C#
// C# program to swap using XOR using System; class GFG { public static void Main() { int x = 10; int y = 5; // Code to swap 'x' (1010) // and 'y' (0101) // x now becomes 15 (1111) x = x ^ y; // y becomes 10 (1010) y = x ^ y; // x becomes 5 (0101) x = x ^ y; Console.WriteLine( "After swap: x = " + x + ", y = " + y); } } // This code is contributed by ajit |
PHP
<?php // Driver Code $x = 10; $y = 5; // Code to swap 'x' (1010) // and 'y' (0101) // x now becomes 15 (1111) $x = $x ^ $y ; // y becomes 10 (1010) $y = $x ^ $y ; // x becomes 5 (0101) $x = $x ^ $y ; echo "After Swapping: x = " , $x , ", " , "y = " , $y ; // This code is contributed by aj_36 ?> |
Javascript
<script> // Javascript code to swap using XOR let x = 10, y = 5; // Code to swap 'x' (1010) and 'y' (0101) x = x ^ y; // x now becomes 15 (1111) y = x ^ y; // y becomes 10 (1010) x = x ^ y; // x becomes 5 (0101) document.write( "After Swapping: x =" + x + ", y=" + y); // This code is contributed by Mayank Tyagi </script> |
输出
After Swapping: x =5, y=10
上述方法存在的问题 1) 如果其中一个数字为0，则基于乘法和除法的方法不起作用，因为不管另一个数字是什么，乘积都变为0。 2) 两种算术解都可能导致算术溢出。如果x和y太大，则加法和乘法可能超出整数范围。 3) 当我们使用指向变量的指针并进行函数交换时，当两个指针指向同一个变量时，上述所有方法都会失败。让我们看看如果两者都指向同一个变量，在这种情况下会发生什么。
//基于位异或的方法 x=x^x；//x变成0 x=x^x；//x仍然是0 x=x^x；//x仍然是0 //基于算法的方法 x=x+x；//x变成了2x x=x–x；//x变成0 x=x–x；//x仍然是0
让我们看看下面的节目。
C++
#include <bits/stdc++.h> using namespace std; void swap( int * xp, int * yp) { *xp = *xp ^ *yp; *yp = *xp ^ *yp; *xp = *xp ^ *yp; } // Driver code int main() { int x = 10; swap(&x, &x); cout << "After swap(&x, &x): x = " << x; return 0; } // This code is contributed by rathbhupendra |
C
#include <stdio.h> void swap( int * xp, int * yp) { *xp = *xp ^ *yp; *yp = *xp ^ *yp; *xp = *xp ^ *yp; } int main() { int x = 10; swap(&x, &x); printf ( "After swap(&x, &x): x = %d" , x); return 0; } |
JAVA
class GFG { static void swap( int [] xp, int [] yp) { xp[ 0 ] = xp[ 0 ] ^ yp[ 0 ]; yp[ 0 ] = xp[ 0 ] ^ yp[ 0 ]; xp[ 0 ] = xp[ 0 ] ^ yp[ 0 ]; } // Driver code public static void main(String[] args) { int [] x = { 10 }; swap(x, x); System.out.println( "After swap(&x, &x): x = " + x[ 0 ]); } } // This code is contributed by Rajput-Ji |
蟒蛇3
def swap(xp, yp): xp[ 0 ] = xp[ 0 ] ^ yp[ 0 ] yp[ 0 ] = xp[ 0 ] ^ yp[ 0 ] xp[ 0 ] = xp[ 0 ] ^ yp[ 0 ] # Driver code x = [ 10 ] swap(x, x) print ( "After swap(&x, &x): x = " , x[ 0 ]) # This code is contributed by SHUBHAMSINGH10 |
C#
// C# program to implement // the above approach using System; class GFG { static void swap( int [] xp, int [] yp) { xp[0] = xp[0] ^ yp[0]; yp[0] = xp[0] ^ yp[0]; xp[0] = xp[0] ^ yp[0]; } // Driver code static void Main() { int [] x = { 10 }; swap(x, x); Console.WriteLine( "After swap(&x," + "&x): x = " + x[0]); } } // This code is contributed by divyeshrabadiya07 |
PHP
<?php function swap(& $xp , & $yp ) { $xp = $xp ^ $yp ; $yp = $xp ^ $yp ; $xp = $xp ^ $yp ; } // Driver Code $x = 10; swap( $x , $x ); print ( "After swap(&x, &x): x = " . $x ); // This code is contributed // by chandan_jnu ?> |
Javascript
<script> function swap(xp,yp) { xp[0] = xp[0] ^ yp[0]; yp[0] = xp[0] ^ yp[0]; xp[0] = xp[0] ^ yp[0]; } // Driver code let x=[10]; swap(x, x); document.write( "After swap(&x, &x): x = " + x[0]); // This code is contributed by unknown2108 </script> |
输出
After swap(&x, &x): x = 0
在许多标准算法中，可能需要将变量本身交换。例如，请参见 这 实施 快速排序 在这里我们可以交换一个变量。通过在交换之前设置条件，可以避免上述问题。
C++
#include <bits/stdc++.h> using namespace std; void swap( int * xp, int * yp) { // Check if the two addresses are same if (xp == yp) return ; *xp = *xp + *yp; *yp = *xp - *yp; *xp = *xp - *yp; } // Driver Code int main() { int x = 10; swap(&x, &x); cout << "After swap(&x, &x): x = " << x; return 0; } // This code is contributed by rathbhupendra |
C
#include <stdio.h> void swap( int * xp, int * yp) { if (xp == yp) // Check if the two addresses are same return ; *xp = *xp + *yp; *yp = *xp - *yp; *xp = *xp - *yp; } int main() { int x = 10; swap(&x, &x); printf ( "After swap(&x, &x): x = %d" , x); return 0; } |
JAVA
// Java program of above approach class GFG { static void swap( int xp, int yp) { if (xp == yp) // Check if the two addresses are same return ; xp = xp + yp; yp = xp - yp; xp = xp - yp; } // Driver code public static void main(String[] args) { int x = 10 ; swap(x, x); System.out.println( "After swap(&x, &x): x = " + x); } } // This code is Contributed by Code_Mech. |
蟒蛇3
# Python3 program of above approach def swap(xp, yp): # Check if the two addresses are same if (xp[ 0 ] = = yp[ 0 ]): return xp[ 0 ] = xp[ 0 ] + yp[ 0 ] yp[ 0 ] = xp[ 0 ] - yp[ 0 ] xp[ 0 ] = xp[ 0 ] - yp[ 0 ] # Driver Code x = [ 10 ] swap(x, x) print ( "After swap(&x, &x): x = " , x[ 0 ]) # This code is contributed by SHUBHAMSINGH10 |
C#
// C# program of above approach using System; class GFG { static void swap( int xp, int yp) { if (xp == yp) // Check if the two addresses are same return ; xp = xp + yp; yp = xp - yp; xp = xp - yp; } // Driver code public static void Main() { int x = 10; swap(x, x); Console.WriteLine( "After swap(&x, &x): x = " + x); } } // This code is Contributed by Code_Mech. |
PHP
<?php function swap( $xp , $yp ) { // Check if the two addresses // are same if ( $xp == $yp ) return ; $xp = $xp + $yp ; $yp = $xp - $yp ; $xp = $xp - $yp ; } // Driver Code $x = 10; swap( $x , $x ); echo ( "After swap(&x, &x): x = " . $x ); return 0; // This code is contributed // by Code_Mech. |
Javascript
<script> function swap(xp, yp) { // Check if the two addresses are same if (xp == yp) return ; xp[0] = xp[0] + yp[0]; yp[0] = xp[0] - yp[0]; xp[0]= xp[0] - yp[0]; } // Driver Code x = 10; swap(x, x); document.write( "After swap(&x , &x) : x = " + x); //This code is contributed by simranarora5sos </script> |
输出
After swap(&x, &x): x = 10
方法3（位运算符和算术运算符的混合） 该想法与中讨论的相同 方法1 但是使用位加法和减法进行交换。
以下是上述方法的实施情况。
C++
// C++ program to swap two numbers. // Including header file. #include <bits/stdc++.h> using namespace std; // Function to swap the numbers. void swap( int & a, int & b) { // same as a = a + b a = (a & b) + (a | b); // same as b = a - b b = a + (~b) + 1; // same as a = a - b a = a + (~b) + 1; } // Driver Code int main() { int a = 5, b = 10; // Function Call swap(a, b); cout << "After swapping: a = " << a << ", b = " << b; return 0; } // This code is contributed by yashbeersingh42 |
JAVA
// Java program to swap two numbers import java.io.*; class GFG { public static void swap( int a, int b) { // same as a = a + b a = (a & b) + (a | b); // same as b = a - b b = a + (~b) + 1 ; // same as a = a - b a = a + (~b) + 1 ; System.out.print( "After swapping: a = " + a + ", b = " + b); } public static void main(String[] args) { int a = 5 , b = 10 ; // Function Call swap(a, b); } } // This code is contributed by yashbeersingh42 |
蟒蛇3
# Python3 program to swap two numbers # Function to swap the numbers def swap(a, b): # Same as a = a + b a = (a & b) + (a | b) # Same as b = a - b b = a + (~b) + 1 # Same as a = a - b a = a + (~b) + 1 print ( "After Swapping: a = " , a, ", b = " , b) # Driver code a = 5 b = 10 # Function call swap(a, b) # This code is contributed by bunnyram19 |
C#
// C# program to swap two numbers using System; class GFG { static void swap( int a, int b) { // same as a = a + b a = (a & b) + (a | b); // same as b = a - b b = a + (~b) + 1; // same as a = a - b a = a + (~b) + 1; Console.Write( "After swapping: a = " + a + ", b = " + b); } static void Main() { int a = 5, b = 10; // Function Call swap(a, b); } } // This code is contributed by divyesh072019 |
Javascript
<script> // Javascript program to swap two numbers function swap(a, b) { // same as a = a + b a = (a & b) + (a | b); // same as b = a - b b = a + (~b) + 1; // same as a = a - b a = a + (~b) + 1; document.write( "After swapping: a = " + a + ", b = " + b); } let a = 5, b = 10; // Function Call swap(a, b); // This code is contributed by suresh07. </script> |
PHP
<?php // Driver Code $a = 5; $b = 10; echo ( "Before swap(a and b) " . $a . "and" . $b . "<br>" ); // same as a = a + b $a = ( $a & $b ) + ( $a | $b ); // same as b = a - b $b = $a + (~ $b ) + 1; // same as a = a - b $a = $a + (~ $b ) + 1; echo ( "After swap(a and b) " . $a . "and" . $b ); return 0; ?> |
输出
After swapping: a = 10, b = 5
要了解有关在一行中交换两个变量的更多信息，请单击 在这里 .
如果您发现任何不正确的地方，或者您想分享有关上述主题的更多信息，请写评论
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