W3Schools 试用编辑器 - W3Schools 中文教程

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

struct list {
  int *data; // Points to the memory where the list items are stored
  int numItems; // Indicates how many items are currently in the list
  int size; // Indicates how many items fit in the allocated memory
};

void addToList(struct list *myList, int item);

int main() {
  struct list myList;
  int amount;

// Create a list and start with enough space for 10 items
  myList.numItems = 0;
  myList.size = 10;
  myList.data = malloc(myList.size * sizeof(int));

// Find out if memory allocation was successful
  if (myList.data == NULL) {
    printf("Memory allocation failed");
    return 1; // Exit the program with an error code
  }
  
  // Add any number of items to the list specified by the amount variable
  amount = 44;
  for (int i = 0; i < amount; i++) {
    addToList(&myList, i + 1);
  }

// Display the contents of the list
  for (int j = 0; j < myList.numItems; j++) {
    printf("%d ", myList.data[j]);
  }

// Free the memory when it is no longer needed
  free(myList.data);
  myList.data = NULL;
  return 0;
}

// This function adds an item to a list
void addToList(struct list *myList, int item) {

// If the list is full then resize the memory to fit 10 more items
  if (myList->numItems == myList->size) {
    myList->size += 10;
    myList->data = realloc( myList->data, myList->size * sizeof(int) );
  }

// Add the item to the end of the list
  myList->data[myList->numItems] = item;
  myList->numItems++;
}