50PointersStructure.c

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

#define MAX_SIZE 20

typedef struct User {
    char *login;
    char *password;
    int id;
} User;

void jsonUser(User *user) {
    printf("{id: %d, login: \"%s\", password: \"%s\"}\n",
           user->id, user->login, user->password);
}

void freeUsersArray(User** users, unsigned size) {
    unsigned i;
    for (i = 0; i < size; i++) {
        free((*users)[i].login);
        free((*users)[i].password);
    }
    free(*users);
}

void main() {
    User *users = NULL;
    unsigned size;
    char buffer[128];
    unsigned i;

    printf("Enter number of users: ");
    scanf("%d", &size);

    size = size <= MAX_SIZE? size: MAX_SIZE;
    users = (User*) malloc(size * sizeof(User));

    for (i = 0; i < size; i++) {
        printf("user #%d\nname: ", i);
        scanf("%127s", buffer);
        users[i].id = i;
        users[i].login = (char*) malloc(strlen(buffer) + 1);
        strcpy(users[i].login, buffer);
        printf("password: ");
        scanf("%127s", buffer);
        users[i].password = (char*) malloc(strlen(buffer) + 1);
        strcpy(users[i].password, buffer);
    }

    for (i = 0; i < size; i++) {
        jsonUser(&users[i]);
    }

    freeUsersArray(&users, size);
    getch();
}