I am a complete beginner in C language.

I want to make a program that three student enter their student ID, name, score then this program print their student ID, name, score, total score and highest score.

I want to also use a subprogram like below:

#include<stdio.h>
#define SIZE 3

int best_score(float a, float b);

struct student {
    int number;
    char name[20];
    double grade;
};

int main(){
    struct student list[SIZE];
    int i;

    for(i = 0; i < SIZE; i  ){
        printf("enter your student ID : ");
        scanf("%d", &list[i].number);
        printf("enter your name : ");
        scanf("%s", list[i].name);
        printf("enter your score : ");
        scanf("%lf", &list[i].grade);

        printf("\n");
    }

    printf("\n");

    for(i = 0; i< SIZE; i  ){
        printf("ID: %d, name: %s, score: %f\n", list[i].number, list[i].name, list[i].grade);
    }

    for(i = 0; i< SIZE; i  ){
        float max = best_score(list[i], i);
        float temp = all_score(list[i], i);
    }

    return 0;
}

int best_score(float list[i], int i){
    float max=0;

    if (max < list[i]) {
        max = list[i];
    }

    return max;
}

int all_score(float list[i], int i){
    float temp=0;

    temp  = list[i];

    return temp;
}

this program's error code is like below: enter image description here

CodePudding user response：

best_score and all_scores should take an array and do the looping themselves, they shouldn't be called in a loop.

The array should be struct student, not float, since you don't have an array of just float.

The functions should return float, not int.

#include<stdio.h>
#define SIZE 3

struct student {
    int number;
    char name[20];
    double grade;
};

float best_score(struct student a[], size_t n);
float all_score(struct student a[], size_t n);

int main(){
    struct student list[SIZE];
    int i;

    for(i = 0; i < SIZE; i  ){
        printf("enter your student ID : ");
        scanf("%d", &list[i].number);
        printf("enter your name : ");
        scanf("%s", list[i].name);
        printf("enter your score : ");
        scanf("%lf", &list[i].grade);

        printf("\n");
    }

    printf("\n");

    for(i = 0; i< SIZE; i  ){
        printf("ID: %d, name: %s, score: %f\n", list[i].number, list[i].name, list[i].grade);
    }

    float max = best_score(list, SIZE);
    float temp = all_score(list, SIZE);
    printf("Best score: %f, All scores: %f\n", max, temp);

    return 0;
}

float best_score(struct student list[], size_t n){
    float max=0;

    for (size_t i = 0; i < n; i  ) {
        if (max < list[i].grade) {
            max = list[i].grade;
        }
    }

    return max;
}

float all_score(struct student list[], size_t n){
    float temp=0;

    for (size_t i = 0; i < n; i  ) {
        temp  = list[i].grade;
    }

    return temp;
}

CodePudding user response：

There are many issues:

• score is a double, therefore you need to use double everytime a score is involved. Right now you're using int (like in int best_score(float a, float b);), float (like in float max=0;) and double (like in double grade;).
• the declaration int best_score(float a, float b); doesn't match the implementation int best_score(float list[i], int i)
• The implementation best_score cannot work. You need to scan all SIZE scores.
• It's unclear what all_score is supposed to do (maybe return the sum of all scores?)

You probably want some something like this for best_score

double best_score(struct student list[])
{
  double max = 0;

  for (int i = 0; i < SIZE; i  ) {
    if (max < list[i].grade) {
      max = list[i].grade;
    }
  }

  return max;
}

call it like this:

double max = best_score(list);

Now you should be able to write all_score yourself.