#include <stdio.h>

int main(void)
{
    int a=1, b=2;
    double x1, x2, x3, x4;

    x1 = a / b;                  /* 整数除算 */
    x2 = (double)a / b;          /* 分子を実数化 */
    x3 = a / (double)b;          /* 分母を実数化 */
    x4 = (double)a / (double)b;  /* 分子・分母を実数化 */

    printf("a = %d, b = %d\n", a, b);
    printf("x1 = %f, x2 = %f, x3 = %f, x4 = %f\n", x1, x2, x3, x4);
    return 0;
}