具有功能和结构的c数组

Question

I have to make c array through functions and structures. But I am not sure, how should I do that. Could you give me some tips?

Here is my version without functions and structures.

int main(int argc, char** argv) {

    int i;
    float max, min, sum;
    float numbers[10];

    for(i=0;i<10;i++)
    {
        printf("put numbers: ");
        scanf("%f",&numbers[i]);
    }

   for(i=0;i<10;i++)
        printf("%.2f \n ",numbers[i]);

    min = numbers[0];
    max = numbers[0];
    sum = 0;

    for(i=0;i<10;i++)
    {
        if(numbers[i]>max)
            max = numbers[i];
        if(numbers[i]<min)
            min = numbers[i];
        sum = sum + numbers[i];
    }

    printf("Minimum=%.2f; Maximum=%.2f; Prumer=%.2f",min,max,sum/10);

    return (EXIT_SUCCESS);
}

Answer 1

struct t_numbers {
  float max;
  float min;  
};

t_numbers num [10];

...
for (int i=0; i<10; i++) {
  num[i].max = 0;
  num[i].min = 0;
}

You must get the idea. ;-) Cheers

Answer 2

Something like this...

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

typedef struct
{
    float max;
    float min;
    float avg;
} Result_t;

void ask_numbers(float *numbers, int nelem)
{
    int i;

    for(i=0;i<nelem;i++)
    {
        printf("put numbers: ");
        scanf("%f",&numbers[i]);
    }
}

Result_t calculate(const float *numbers, int nelem)
{
    int i;
    float sum = 0.0f;
    Result_t res = {0};

    res.min = numbers[0];
    res.max = numbers[0];

    for(i=0; i<nelem; i++) {
        if(numbers[i] > res.max)
            res.max = numbers[i];

        if(numbers[i] < res.min)
            res.min = numbers[i];

        sum += numbers[i];
    }

    res.avg = sum / nelem;

    return res;
}

int main(int argc, char** argv) {

    int i;
    float numbers[10];
    Result_t res;

    ask_numbers(numbers, 10);

    for(i=0;i<10;i++)
        printf("%.2f \n ",numbers[i]);


    res = calculate(numbers, 10);

    printf("Minimum=%.2f; Maximum=%.2f; Prumer=%.2f", res.min, res.max, res.avg);

    return(0);
}

On the second function, the struct could have been passed by pointers instead to be returned by copy. But since the struct is small, the overhead is small.

Cheers.

Answer 3

Since you want an array of structs , you can create a singular struct holding one float member:

typedef struct {
    float number;
} number_t;

Note: Having a struct with one member is awkward, but it will suffice for your needs. It would be better to just declare a float array and have that in one struct, but that would not be an array of structs.

You can then create an array of structs:

number_t numbers[10];

Which has 10 members of type number_t . You can then have this array sit inside a larger struct which holds the max, min and average values:

typedef struct {
    number_t numbers[MAXNUM];
    size_t size;
    float max;
    float min;
    float avg;
} numbers_t;

You can then pass something like numbers_t N to main() , which declares a struct member of type numbers_t . This member holds the whole struct.

In order to modify the contents of N , you can simply pass a pointer to it, and change the contents by accessing the address of this pointer.

Additionally, it is always good to check result of scanf() , just to be safe.

Here is some example code:

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

#define MAXNUM 10

typedef struct {
    float number;
} number_t;

typedef struct {
    number_t numbers[MAXNUM];
    size_t size;
    float max;
    float min;
    float avg;
} numbers_t;

/* functions which pass pointer to N */
void initialize_struct(numbers_t *N);
void print_details(numbers_t *N);
void print_array(numbers_t *N);
void get_input(numbers_t *N);
void get_data(numbers_t *N);

int main(void) {
    numbers_t N;

    initialize_struct(&N);

    get_input(&N);

    get_data(&N);

    print_details(&N);

    return 0;
}

void print_details(numbers_t *N) {
    print_array(N);
    printf("\nMaximum: %.2f\n", N->max);
    printf("\nMinimum: %.2f\n", N->min);
    printf("\nAverage: %.2f\n", N->avg);
}

void print_array(numbers_t *N) {
    printf("\nYour numbers:\n");
    for (size_t i = 0; i < N->size; i++) {
        printf("%.2f\n", N->numbers[i].number);
    }
}

void get_input(numbers_t *N) {
    printf("Enter %zu numbers:\n", N->size);
    for (size_t i = 0; i < N->size; i++) {
        if (scanf("%f", &N->numbers[i].number) != 1) {
            printf("Invalid number entered\n");
            exit(EXIT_FAILURE);
        }
    }
}

void get_data(numbers_t *N) {
    float sum = 0.0f;
    N->max = N->min = N->numbers[0].number;

    for (size_t i = 1; i < N->size; i++) {
        if (N->numbers[i].number > N->max) {
            N->max = N->numbers[i].number;
        } else if (N->numbers[i].number < N->min) {
            N->min = N->numbers[i].number;
        }
        sum += N->numbers[i].number;
    }
    N->avg = sum / N->size;
}

void initialize_struct(numbers_t *N) {
    N->size = MAXNUM;

    for (size_t i = 0; i < N->size; i++) {
        N->numbers[i].number = 0.0f;
    }

    N->max = 0.0f;
    N->min = 0.0f;
    N->avg = 0.0f;
}

Example input:

Enter 10 numbers:
5.43
4.32
9.43
10.43
7.43
2.34
1.54
8.43
6.43
4.32

Output:

Your numbers:
5.43
4.32
9.43
10.43
7.43
2.34
1.54
8.43
6.43
4.32

Maximum: 10.43

Minimum: 1.54

Average: 5.47