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Topic: Swapping of two variable without third variable C (Read 3926 times) |
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adamblack
Newbie
Posts: 3
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Swapping of two variable without third variable C
« on: Feb 3rd, 2012, 1:49am » |
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//swapping without third variable
//A tricky way of swapping
#include<stdio.h>
#include<conio.h>
void main()
{
int a=10,b=20;
clrscr();
printf("Before swapping:\na=%d\nb=%d",a,b);
a=b+a;
b=a-b;
a=a-b;
printf("\nAfter swapping:\na=%d\nb=%d",a,b);
getch();
}
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Grimbal
wu::riddles Moderator
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Posts: 7527
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Re: Swapping of two variable without third variabl
« Reply #1 on: Feb 3rd, 2012, 2:28am » |
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OK, as a little puzzle "how to swap variables without extra space", this is one solution.
But as a programming trick, I wouldn't use it. It is less readable and is likely to be a bit slower than the standard method using a temporary variable.
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adamblack
Newbie
Posts: 3
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Re: Swapping of two variable without third variabl
« Reply #2 on: Feb 3rd, 2012, 2:36am » |
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yes you are right
this question was asked to me in my interview to check my IQ but i could not solve it at that time. i took about 30 min when i came out.
i would like to know if you have any other technique to do this.
also would like question like it.............
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| « Last Edit: Feb 3rd, 2012, 5:17am by Grimbal » |
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Grimbal
wu::riddles Moderator
Uberpuzzler
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Posts: 7527
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Re: Swapping of two variable without third variabl
« Reply #3 on: Feb 3rd, 2012, 2:41am » |
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Another classical way is:
a ^= b;
b ^= a;
a ^= b;
BTW, links to irrelevant web sites are against this forum's netiquette.
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adamblack
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Posts: 3
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Re: Swapping of two variable without third variabl
« Reply #4 on: Feb 3rd, 2012, 2:45am » |
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sure thanks
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phpsomkumar
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Posts: 2
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Re: Swapping of two variable without third variabl
« Reply #5 on: Mar 29th, 2012, 9:45pm » |
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#include<stdio.h>
#include<conio.h>
void main()
{
int x=10,y=20;
clrscr();
printf("Before swapping:\nx=%d\ny=%d",x,y);
x=y+x;
y=x-y;
x=x-y;
printf("\nAfter swapping:\nx=%d\ny=%d",x,y);
getch();
}
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phpsomkumar
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Posts: 2
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Re: Swapping of two variable without third variabl
« Reply #6 on: Mar 29th, 2012, 9:49pm » |
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<?php
$x = 10;
$y = 20;
$x = $x+$y;
$y = $x – $y;
$x = $x – $y;
?>
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