#include <stdio.h>
#include <math.h>
int isPrime(int n)
{
int i; if (n < 2)return 0;
int k = (int)sqrt((double)n); //提高效率 for (i = 2; i <= k; i++) {if (n % i == 0)
? return 0;
} return 1;}
int main()
{
int i = 3, ct = 0; while (ct < 1000) {if (isPrime(i) && isPrime(i + 2))
{
? ct++;
? printf("第 %d 對:%d/%d\n", ct, i, i + 2);
}
i += 2;
} return 0;}