以十进制，八进制和十六进制打印100

#include <stdio.h>
int main(void)
{
    int x = 100;

    printf("dec = %d; octal = %o; hex = %x/n", x, x, x);
    printf("dec = %d; octal = %#o; hex = %#x/n", x, x, x);

    return 0;
}