(C++编程)用筛选法求100之内的素数

#include <iostream>
using namespace std;

int main()
{
bool prime[105]; int i;
memset(prime,true,sizeof(prime));
prime[1] = false;
for (i = 2; i <= 50; i++)
for (int j = 2;i*j <= 100; j++)
prime[i*j] = false;
for (i = 1; i <= 100; i++)
if (prime[i])
printf("%d ",i);
putchar('\n');
return 0;
}

亦力把里

#include <iostream>
#include <cmath>
using namespace std;

void main()
{
bool b_is;
int i,j;
b_is = false;
for (i = 1; i <= 100; i++){
b_is = false;
for (j = 2;j<= sqrt(i); j++)
{
if(i%j == 0){
b_is = true;
break;
}
}
if(b_is)
cout<<j<<" ";
}
return 0;
}

#include<iostream.h>
#include<math.h>
int main()
{
int i,j,k