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Question
`How to swap two variables, without using third variable ?`
Question Submitted By :: C-Code
I also faced this Question!!     Answer Posted By

# 1
Hi this question was asked in my interview.
Ans is :

a=a+b;
b=a-b;
a=a-b;

Any other solution?

 Is This Answer Correct ? 1713 Yes 218 No
Swapna

# 2
use xor to swap

a = a^b
b= a^b
a= a^b

 Is This Answer Correct ? 532 Yes 161 No
Guest

# 3
Ans is :

a=a*b;
b=a/b;
a=a/b;

 Is This Answer Correct ? 525 Yes 178 No
Somasekhar

# 4
a=a+b;
b=a-b;
a=a-b

 Is This Answer Correct ? 292 Yes 58 No
Kiran

# 5
x = x + y;

y = x - y;

x = x - y;

 Is This Answer Correct ? 104 Yes 23 No
Mohit

# 6
Only the Xor answer (#2) is correct (in cases where the
variables are the same size). With all the other answers,
you could run into over/under flow problems.
A = 01111111
B = 01111101

A = A^B = 00000010
B = A^B = 01111111 (Original A)
A = A^B = 01111101 (Original B)

 Is This Answer Correct ? 87 Yes 21 No
Bruce Tuskey

# 7
a=b-a+(b=a);
 Is This Answer Correct ? 113 Yes 76 No
Partha

# 8
2 one will work correct
 Is This Answer Correct ? 80 Yes 44 No
Gowtham

# 9
void main()
{
int a,b;
printf("Enter two number : ");
scanf("%d%d",&a,&b);
a=a+b;
b=a-b;
a=a-b;
printf("The swap number is : %d %d",a,b);
getch();
}

 Is This Answer Correct ? 39 Yes 9 No
Pavan.

# 10
Answer no 12 is wrong. the logic fails when a=0;
 Is This Answer Correct ? 41 Yes 17 No
Yash

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