Question

Given N numbers, write a function that finds out if there is at least one prime among them and returns it, else returns 0.



A naive approach would check each number for prime- ness. Can you do better ?​

Answer 1

Answer:

#include

int prime(int); // Declera prime function

int main()

int num;

printf(Enter a number?\n); // Get a input number

scanf(%d, &num);

printf(%d\n,prime(num)); // Call the prime funciton

return 0;

/*

Prime numbers is a number which has only two factors 1 and itself.

*/

int prime(int n)

int i,c=0;

if(n<2) if="" n="" is="" 0,1="" return="">

return 0;

for(i=2;i<(n )+1;i++)="" loop="" from="" 2="" to="" (n/2)+1="" as="" n="" cannot="" be="" divisible="" after="">

if(n%i==0) // If n is divisible by i

return 0; // Return 0. (since i is a factor of n)