C language: implements a function to determine whether a number is a prime number.

C language: implements a function to determine whether a number is a prime number.
Implement a function to determine whether a number is a prime number. Program:

# Include <stdio. h> # include <math. h> int prime (int num) // prime indicates the prime number {int I = 0; int k = 0; k = sqrt (num); for (I = 2; I <= k; I ++) {if (num % I = 0) {return 0 ;}} return 1 ;}int main () {int num; int ret; printf ("enter a positive integer greater than 1:"); scanf ("% d", & num); ret = prime (num); if (ret = 1) {printf ("% d is a prime number \ n", num);} else {printf ("% d is not a prime number \ n", num);} return 0 ;}

 

Result 1: Enter a positive integer greater than 1. If 88 is not a prime number, press any key to continue... result 2: enter a positive integer greater than 1. If 1717 is a prime number, press any key to continue...