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;

How to reverse a String without using C functions ?

33 Answers   Matrix, TCS, Wipro,

What is data _null_? ,Explain with code when u need to use it in data step programming ?

0 Answers   Abbott,

main( ) { static int a[ ] = {0,1,2,3,4}; int *p[ ] = {a,a+1,a+2,a+3,a+4}; int **ptr = p; ptr++; printf(“\n %d %d %d”, ptr-p, *ptr-a, **ptr); *ptr++; printf(“\n %d %d %d”, ptr-p, *ptr-a, **ptr); *++ptr; printf(“\n %d %d %d”, ptr-p, *ptr-a, **ptr); ++*ptr; printf(“\n %d %d %d”, ptr-p, *ptr-a, **ptr); }

2 Answers   Persistent,

void main() { void *v; int integer=2; int *i=&integer; v=i; printf("%d",(int*)*v); }

1 Answers   Honeywell,

char *someFun1() { char temp[ ] = “string"; return temp; } char *someFun2() { char temp[ ] = {‘s’, ‘t’,’r’,’i’,’n’,’g’}; return temp; } int main() { puts(someFun1()); puts(someFun2()); }

2 Answers  

main() { char *p = "hello world"; p[0] = 'H'; printf("%s", p); } a. Runtime error. b. “Hello world” c. Compile error d. “hello world”

5 Answers   HCL,

main() { int c = 5; printf("%d", main||c); } a. 1 b. 5 c. 0 d. none of the above

2 Answers   HCL,

char inputString[100] = {0}; To get string input from the keyboard which one of the following is better? 1) gets(inputString) 2) fgets(inputString, sizeof(inputString), fp)

1 Answers  

plz send me all data structure related programs

2 Answers  

void main() { char a[]="12345\0"; int i=strlen(a); printf("here in 3 %d\n",++i); }

3 Answers  

union u { union u { int i; int j; }a[10]; int b[10]; }u; main() { printf("\n%d", sizeof(u)); printf(" %d", sizeof(u.a)); // printf("%d", sizeof(u.a[4].i)); } a. 4, 4, 4 b. 40, 4, 4 c. 1, 100, 1 d. 40 400 4

3 Answers   HCL,

Link list in reverse order.

8 Answers   NetApp,