c语言入门的最后一道题，能力有限，实在是找不到问题的所在，求大神解答

Question

#include <stdio.h>

int sumstring()

{

    int i;

    int sum = 0;

    extern score[];

    for(i=0;i<10;i++)

        sum+=score[i];

    return sum;  

}

double averagestring()

{

    double average;

    average = sumstring()/10;

    return average;

}

int string()

{

    int i,j;

    int highest,lowest;

    extern score[];

    for(i=9;i>=0;i--)

    {

        for(j=0;j<10;j++)

        {   

            int temp;

            if(score[j]<score[j+1])

            {

                temp=score[j];

                score[j]=score[j+1];

                score[j+1]=temp;

            }

        }    

    }

    highest=score[0];

    lowest=score[9];

    printf("最高分:%d\n",highest);

    printf("最低分%d\n",lowest);

    printf("考试成绩排序如下\n");

    for(i=0,i<10,i++)

    {

        if(i!=9)

            printf("%d ",score[i]);

        else

            printf("%d",score[9]);

    }

    return 0;

}

int main()

{

    int score[]={67,98,75,63,82,79,81,91,66,84};

    printf("班级总分：%d",sumstring());

    printf("班级平均分：%f",averagestring());

    string();

    return 0;

}

Answer 1

#include <stdio.h>int sumstring(int score[]){    int i;    int sum = 0;  //  extern score[];    for(i=0;i<10;i++)        sum+=score[i];    return sum; }double averagestring(int score[]){    double average;    average = sumstring(score)/10;    return average;}int string(int score[]){    int i,j;    int highest,lowest;    //extern score[];    for(i=9;i>=0;i--)    {        for(j=0;j<10;j++)        {              int temp;            if(score[j]<score[j+1])            {                temp=score[j];                score[j]=score[j+1];                score[j+1]=temp;            }        }       }    highest=score[0];    lowest=score[9];    printf("最高分:%d\n",highest);    printf("最低分%d\n",lowest);    printf("考试成绩排序如下\n");    for(i=0;i<10;i++)    {        if(i!=9)            printf("%d ",score[i]);        else            printf("%d",score[9]);    }    return 0;}int main(){    int score[]={67,98,75,63,82,79,81,91,66,84};    printf("班级总分：%d",sumstring(score));    printf("班级平均分：%f",averagestring(score));    string(score);    return 0;}

Answer 2

其实你可以将score数组弄成全局的，为何你想用extern关键字？