#include<stdio.h>
#include<stdlib.h>

#if 0
//struct_1 在main函式中定義結構體，並實現功能
int main(void)
{
    struct results
    {
        float interim_results;
        float end_results;
        float average_scores;
    }st;

    printf("input interim_results:");
    scanf("%f",&st.interim_results);

    printf
 
("input end_results:");
    scanf("%f",&st.end_results);

    st.average_scores = (st.interim_results+st.end_results)/2;
    printf("%.2f\n",st.average_scores);

    return 0;
}
#endif

#if 0
//struct_2 結構體指標
int main(void)
{
    struct results
    {
        float interim_results;
        float end_results;
        float
 
 average_scores;
    }; //這裡不能有結構體變數名st

    struct results *st = malloc(sizeof(struct results));

    printf("input interim_results:");
    scanf("%f",&st->interim_results);// ->

    printf("input end_results:");
    scanf("%f",&st->end_results);

    st->average_scores = (st->interim_results+st->end_results)/2
 
;
    printf("%.2f\n",st->average_scores);

    return 0;
}
#endif

#if 0
//struct_3 在main函式外面建立結構體

struct results
    {
        float interim_results;
        float end_results;
        float average_scores;
    }; //這裡不能有結構體變數名st

int foo(float *interim_results,float *end_results,float *average_scores)
{
    *average_scores = (*interim_results+*end_results)/2;
}

int main(void)
{
    struct results *st = malloc(sizeof(struct results));

    printf("input interim_results:");
    scanf("%f",&st->interim_results);// ->

    printf("input end_results:");
    scanf("%f",&st->end_results);

    foo(&st->interim_results,&st->end_results,&st->average_scores);
    printf("%.2f\n",st->average_scores);

    return 0;
}
#endif

#if 0
//struct_4 構建沒有引數和返回值的函式,更高階封裝

struct results
    {
        float interim_results;
        float end_results;
        float average_scores;
    }; //這裡不能有結構體變數名st

void foo()
{
    struct results *st = malloc(sizeof(struct results));

    printf("input interim_results:");
    scanf("%f",&st->interim_results);// ->

    printf("input end_results:");
    scanf("%f",&st->end_results);

    st->average_scores = (st->interim_results+st->end_results)/2;

    printf("%.2f\n",st->average_scores);
}

int main(void)
{
    foo();
    return 0;
}
#endif


#if 0
//struct_5 在main函式外面建立結構體,構建傳遞結構體指標並返回void的函式foo

struct results
    {
        float interim_results;
        float end_results;
        float average_scores;
    }; //這裡不能有結構體變數名st

void foo(struct results *st)
{
    printf("input interim_results:");
    scanf("%f",&st->interim_results);// ->

    printf("input end_results:");
    scanf("%f",&st->end_results);

    st->average_scores = (st->interim_results+st->end_results)/2;
}

int main(void)
{
    struct results *st = malloc(sizeof(struct results));
    foo(st);
    printf("%.2f\n",st->average_scores);

    return 0;
}
#endif


#if 1
//struct_5 在main函式外面建立結構體,構建傳遞結構體指標並結構體指標的函式foo

struct results
    {
        float interim_results;
        float end_results;
        float average_scores;
    }; //這裡不能有結構體變數名st

struct results *foo()
{
    struct results *st = malloc(sizeof(struct results));
    printf("input interim_results:");
    scanf("%f",&st->interim_results);// ->

    printf("input end_results:");
    scanf("%f",&st->end_results);

    st->average_scores = (st->interim_results+st->end_results)/2;

    return st;
}

int main(void)
{
    struct results *st;
    st = foo();

    printf("%.2f\n",st->average_scores);

    return 0;
}
#endif