次のテスト用のmainを含む関数群を必ず使用すること

#include <stdio.h>

/*fraction_t型の定義*/
typedef struct {
    int numerator; /*分子*/
    int denominator; /*分母*/
} fraction_t;

/*式と答えを表示する　a ope b = c*/
void printcheckfraction(fraction_t a, char ope, fraction_t b, fraction_t c)
{
    printf("(%d/%d) %c (%d/%d) = (%d/%d)\n",
        a.numerator,a.denominator, ope,
        b.numerator,b.denominator,
        c.numerator,c.denominator
    );
}

/*四則演算のチェック用関数　a, b にて四則演算を行い，式を表示する*/
void checkfraction(fraction_t a, fraction_t b)
{
    fraction_t c;
    c=addFraction(a,b);
    printcheckfraction(a,'+',b,c);
    c=subtractFraction(a,b);
    printcheckfraction(a,'-',b,c);
    c=subtractFraction(b,a);
    printcheckfraction(b,'-',a,c);

    c=multiplyFraction(a,b);
    printcheckfraction(a,'*',b,c);
    c=divideFraction(a,b);
    printcheckfraction(a,'/',b,c);
    c=divideFraction(b,a);
    printcheckfraction(b,'/',a,c);
    printf("\n");
}

int main()
{
    fraction_t a={1,6};
    fraction_t b={1,3};
    fraction_t am={-1,6};
    fraction_t bm={-1,3};
    fraction_t c={3,4};
    fraction_t d={16,3};
    fraction_t cm={-3,4};
    fraction_t dm={-16,3};
    checkfraction(a,b);
    checkfraction(a,bm);
    checkfraction(am,b);
    checkfraction(am,bm);
    checkfraction(c,d);
    checkfraction(c,dm);
    checkfraction(cm,d);
    checkfraction(cm,dm);
    return 0;
}

以下の実行結果が得られたら正解（自分で１つずつ確かめてから課題提出のこと）

/*
(1/6) + (1/3) = (1/2)
(1/6) - (1/3) = (-1/6)
(1/3) - (1/6) = (1/6)
(1/6) * (1/3) = (1/18)
(1/6) / (1/3) = (1/2)
(1/3) / (1/6) = (2/1)

(1/6) + (-1/3) = (-1/6)
(1/6) - (-1/3) = (1/2)
(-1/3) - (1/6) = (-1/2)
(1/6) * (-1/3) = (-1/18)
(1/6) / (-1/3) = (-1/2)
(-1/3) / (1/6) = (-2/1)

(-1/6) + (1/3) = (1/6)
(-1/6) - (1/3) = (-1/2)
(1/3) - (-1/6) = (1/2)
(-1/6) * (1/3) = (-1/18)
(-1/6) / (1/3) = (-1/2)
(1/3) / (-1/6) = (-2/1)

(-1/6) + (-1/3) = (-1/2)
(-1/6) - (-1/3) = (1/6)
(-1/3) - (-1/6) = (-1/6)
(-1/6) * (-1/3) = (1/18)
(-1/6) / (-1/3) = (1/2)
(-1/3) / (-1/6) = (2/1)

(3/4) + (16/3) = (73/12)
(3/4) - (16/3) = (-55/12)
(16/3) - (3/4) = (55/12)
(3/4) * (16/3) = (4/1)
(3/4) / (16/3) = (9/64)
(16/3) / (3/4) = (64/9)

(3/4) + (-16/3) = (-55/12)
(3/4) - (-16/3) = (73/12)
(-16/3) - (3/4) = (-73/12)
(3/4) * (-16/3) = (-4/1)
(3/4) / (-16/3) = (-9/64)
(-16/3) / (3/4) = (-64/9)

(-3/4) + (16/3) = (55/12)
(-3/4) - (16/3) = (-73/12)
(16/3) - (-3/4) = (73/12)
(-3/4) * (16/3) = (-4/1)
(-3/4) / (16/3) = (-9/64)
(16/3) / (-3/4) = (-64/9)

(-3/4) + (-16/3) = (-73/12)
(-3/4) - (-16/3) = (55/12)
(-16/3) - (-3/4) = (-55/12)
(-3/4) * (-16/3) = (4/1)
(-3/4) / (-16/3) = (9/64)
(-16/3) / (-3/4) = (64/9)*/