从键盘输入任意正整数，判断是否素数的c语言

#include"math.h"
main()
{
int m,i,k;
scanf("%d",&m);
k=sqrt(m);
for(i=2;i<=k;i++)
if(m%i==0)break;
if(i>=k+1)printf("%d is a prime number\n",m);
else printf("%d is not a prime number\n",m);
}

#include "stdio.h"
#include "math.h"
int f(int a);
main()
{
int m;
scanf("%d",&m);
if(f(m)) printf("%d是素数\n",m);
else printf("不是素数\n");
}
int f(int a)
{
int y,i;
for(i=2;i<a/2;i++)
{
if(a%i==0) {y=0;break;}
else y=1;
}
return y;
}

//VC中调试通过!

#include <stdio.h>

int isPrime(int n)
{
int i = 2;
for( ; i * i <= n; i = (i + 1) | 1)
if(n % i == 0)
return 0;
return n > 1;