回复 10楼 czz5242199
嗯，确实错了，想当然了，多谢曹哥点醒还以为不会有超过 sqrt(n)的质因数
[fly]存在即是合理[/fly]
程序代码：#include <stdio.h>
#include <math.h>
int main()
{
__int64 i = 3, n, temp, a;
temp = n = 600851475143;
while (1)
{
a = (__int64)sqrt((double)temp);
for (;i <= a;i += 2)
if (temp % i == 0)
break;
if (i > a)
{
printf("%I64d = %I64d\n", temp, n);
break;
}
printf("%I64d * ", i);
temp /= i;
}
return 0;
}