使用多个相同数组的结构-在浮点数中找到平均值

Question

想寻求帮助！我为3个科目（数学，英语和自然科学）打分，可以分为三个不同的组。

我根据建议使用“结构”。

我无法打印每个主题和整个主题的平均值。平均值显示为零。

for (int i = 0; i < num && i < Max_NUM; i++)
{
  for (j = 0; j < 3; j++) 
        { //loop calculating sum of array elements
                        sum=(sum+std[i].subject[j]); //sum of mark for 3 subjects 
                        sum2=sum/num;  
                    std[i].subject[j] =(sum2/Max_Grade)*100; // average mark

                //for total average mark (sub 0 avg mark+ sub 1 avg mark+ sub 2 avg mark)
                totalSUB =(std[i].subject[0]+std[i].subject[1]+std[i].subject[2])/3;
         }
                   //to print 3lines: for average marks of each subject: sub 0, sub 1, sub2  
                  printf("\nAverage mark: %.2f",std[i].subject[j]);  

                  //to print average marks for each subject: sub 0, sub 1, sub2  
                  printf("\nTotalSUB- Average mark: %.2f",totalSUB);  
                   return 0; 
                   }  //end of if

输出错误，如图所示：完整代码如下：

 #include <stdio.h>
        #include <stdlib.h>
        #define Max_Grade 415
        #define Max_NUM 150
                int main()
                {
                    int i,j,num;//variable declaration
                    double avg=0.0,sum=0.0, sum2=0.0, totalSUB=0.0;
                    struct student 
                    {
                         double subject[3];
                    };
                    struct student std[Max_NUM];
                    printf("Enter number of students: ");
                    scanf("%d",&num);
// for loop to read i'th student's j'th subject
for (int i = 0; i < num && i < Max_NUM; i++)
{
  for (j = 0; j < 3; j++) 
  {
     printf("Enter marks of student %d for subject %d: ", i, j);
     scanf("%f", &std[i].subject[j]);
     //sleep(2);
  }
}
for (int i = 0; i < num && i < Max_NUM; i++)
{
  for (j = 0; j < 3; j++) 
        { //loop calculating sum of array elements
                        sum=(sum+std[i].subject[j]); //sum of mark for 3 subjects 
                        sum2=sum/num;  
                    std[i].subject[j] =(sum2/Max_Grade)*100; // average mark

                //for total average mark (sub 0 avg mark+ sub 1 avg mark+ sub 2 avg mark)
                totalSUB =(std[i].subject[0]+std[i].subject[1]+std[i].subject[2])/3;
         }
                   //to print 3lines: for average marks of each subject: sub 0, sub 1, sub2  
                  printf("\nAverage mark: %.2f",std[i].subject[j]);  

                  //to print average marks for each subject: sub 0, sub 1, sub2  
                  printf("\nTotalSUB- Average mark: %.2f",totalSUB);  
                   return 0; 
                   }  //end of if

               } //end of int main()

Answer 1

您将达到如下所示的效果。用您想要的科目构建结构，并为那么多学生分配记忆。在每个学生std的循环中，您可以阅读每个学生的学科标记。同样，您也可以计算平均分数。

struct student {
  int subject[3];
};

struct student std[Max_NUM];

printf("Enter number of students: ");
scanf("%d",&num);

/* for loop to read i'th student's j'th subject*/
for (int i = 0; i < num && i < Max_NUM; i++) {
  for (j = 0; j < 3; j++) {
     printf("Enter marks of student %d for subject %d: ", i, j);
     scanf("%d", &std[i].subject[j]);
  }
}