Answer / dan

if (x & (x-1)) // false only if x is a power of 2

Answer / vadivel

# include <stdio.h>

void main()
{
int n;
scanf("%d",&n);
if( n & (n-1) )
printf("Not a Power of 2");
else
printf("Power of 2");
}

Answer / ataraxic

Previous post -- It's wrong... absolutely...

Answer / phil

if (x && !(x & (x-1)) == 0)

Answer / jb

(x ^ x-1) == ((x << 1) - 1)

Answer / ashutosh

I think
if (x & (x-1)) wont work when number is negative.

Answer / natmat

(~i & (i-1)) == (i - 1))

Answer / fjords

if (int(log(x)) == log(x)) // log is to the base 2

Answer / rahul priyadarshi

#define ISPOW2(x) ((x==1)?1:(x&(x-1)))?0:1

Answer / yevgen

if ((num XOR (num - 1)) == num + num - 1) return true;
else return false;

Predict the Output: int main() { int *p=(int *)2000; scanf("%d",2000); printf("%d",*p); return 0; } if input is 20 ,what will be print

2 Answers  

what will be the position of the file marker? a: fseek(ptr,0,SEEK_SET); b: fseek(ptr,0,SEEK_CUR);

2 Answers  

What is the main difference between STRUCTURE and UNION?

13 Answers   HCL,

posted by surbhi just now main() { float a = 5.375; char *p; int i; p=(char*)&a; for(i=0;i<=3;i++) printf("%02x",(unsigned char) p[i]); } how is the output of this program is :: 0000ac40 please let me know y this output has come

2 Answers   GATE,

write a program in c to merge two array

2 Answers  

#ifdef something int some=0; #endif main() { int thing = 0; printf("%d %d\n", some ,thing); }

1 Answers  

main() { char c; int i = 456; clrscr(); c = i; printf("%d", c); } a. 456 b. -456 c. random number d. none of the above

3 Answers   BrickRed, HCL,

#define SQR(x) x * x main() { printf("%d", 225/SQR(15)); } a. 1 b. 225 c. 15 d. none of the above

3 Answers   HCL,

main() { if (!(1&&0)) { printf("OK I am done."); } else { printf("OK I am gone."); } } a. OK I am done b. OK I am gone c. compile error d. none of the above

3 Answers   HCL,

String copy logic in one line.

11 Answers   Microsoft, NetApp,

main() { int i = 258; int *iPtr = &i; printf("%d %d", *((char*)iPtr), *((char*)iPtr+1) ); }

1 Answers  

how to check whether a linked list is circular.

11 Answers   Microsoft,