c语言数组基本操作

1.源码实现

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

//数组输出
void output(int *arr, int n)
{
    if(n > 0)
    {
        int i;

        for(i=0; i<n-1; i++)
        {
            printf("%d ", arr[i]);
        }

        printf("%d\n", arr[i]);
    }
}

//数组初始化
int init(int **arr, int n)
{
    *arr = (int *)malloc(n*sizeof(int));
    memset(*arr, 0x00, n*sizeof(int));
    return n;
}

//数组扩容
int resize(int **arr, int n)
{
    int *tmp = *arr;

    if(*arr == NULL)
    {
        return 0;
    }

    *arr = (int *)malloc(n*2*sizeof(int));
    memset(*arr, 0x00, n*2*sizeof(int));
    memcpy(*arr, tmp, n*sizeof(int));
    free(tmp);

    return n*2;
}

//数组插入元素
int insert(int **arr, int *size, int n, int elem, int index)
{
    int i;

    if(index < 0 || index > n)
    {
        printf("超出数组实际元素范围\n");
        return n;
    }

    if(n + 1 > *size)
    {
        *size = resize(arr, *size);
    }

    for(i=n-1; i>=index; i--)
    {
        (*arr)[i+1] = (*arr)[i];
    }

    (*arr)[index] = elem;

    return n+1;
}

//数组删除元素
int delete(int *arr, int n, int index)
{
    int i;

    if(index < 0 || index > n)
    {
        printf("超出数组实际元素范围\n");
        return n;
    }

    for(i=index; i<n-1; i++)
    {
        arr[i] = arr[i+1];
    }

    arr[i] = 0x00;

    return n-1;
}

int main()
{
    int *array = NULL;
    int size = 4;
    int n = 0;

    init(&array, size);

    output(array, n);

    n = insert(&array, &size, n, 3, 0);
    output(array, n);

    n = insert(&array, &size, n, 7, 1);
    output(array, n);

    n = insert(&array, &size, n, 9, 2);
    output(array, n);

    n = insert(&array, &size, n, 5, 3);
    output(array, n);

    n = insert(&array, &size, n, 6, 1);
    output(array, n);

    printf("size=%d\n", size);

    return 0;
}

2.编译源码

$ gcc -o example example.c

3.运行及其结果

$ ./example
3
3 7
3 7 9
3 7 9 5
3 6 7 9 5
size=8