Home > Programming > program to swap two numbers with out using temporary variable with in one line

program to swap two numbers with out using temporary variable with in one line

#include <stdio.h>
#include <conio.h>
int main(void)
int a , b;
printf(“Enter two integers: “);
printf(“Before swapping: a=%d,b=%d\n”,a,b);
a=(a+b)-(b=a); //This is just one line
printf(“After swapping: a=%d,b=%d”,a,b);
return 0;
compiled on :gcc logic :simple and tricky
If you have any doubts please add a comment
  1. kiran reddy
    June 14, 2010 at 12:15 pm

    cool prgm man..

  2. August 8, 2010 at 5:25 pm

    excellent.. post some more logics

    • August 8, 2010 at 5:44 pm

      ok.. I do post. Thank you for your compliments

  3. November 26, 2010 at 5:20 am

    This doesn’t work in Visual Studio 2008.

    In the line (a+b)-(b=a), you are relying on (a+b) to complete before (b=a). This is not necessarily true.

    This is because (a+b) and (b=a) has the same precedence. In this case, VS2008 chooses to perform (b=a) first.

    Here’s the generated assembly from a Debug build.

    mov eax,dword ptr [a]
    mov dword ptr [b],eax
    mov ecx,dword ptr [a]
    mov dword ptr [a],ecx

    … Alan

    • November 26, 2010 at 12:10 pm

      Ya you are correct… I wrote that program in GCC compiler. It may not work in VS 2008. I think this may work Once try this way….
      int main(void){
      int a=20;
      int b=10;
      printf(“a = %d, b = %d\n”,a,b);
      a=(a+b)-(b=(a+b)-b); // Here is the simple logic
      printf(“a = %d, b = %d\n “,a,b);
      return 0;

  4. divakar
    February 18, 2012 at 1:05 pm

    very very simple logic thank u vasanth.

  5. shubham pandey
    August 18, 2012 at 7:44 pm

    sir please put some more programs with good logic.

  6. March 19, 2014 at 6:48 pm

    very nice

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  1. October 17, 2010 at 7:53 am
  2. August 31, 2011 at 9:32 am

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