生成0到50000之间的随机偶数

The rand() function returns a pseudo-random integer in the range 0 to RAND_MAX inclusive.（来自man手册）

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
int main (void)
{
    srand(time(NULL));
    printf("%d\n", 2*(rand () % 25000));
    return 0;
}