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C篇的系列文章并不会深入去剖析某个语法，而是介绍C存在着哪些知识点。指针高级也同样如此，介绍指针数组、二重指针、数组指针、函数指针、指针传参。最后使用这几种语法做一个冒泡排序

• 指针数组

#include <stdio.h>

int main(void)
{
    char* chPointer[2] = {"hello", "world"}; // 存储指针的数组
    for(int i = 0; i < 2; i++) {
        printf("%s\n", *(chPointer+i));
    }
}

• 二重指针

#include <stdio.h>
int main(void)
{
    int index = 1;
    int* a = NULL;
    int** b = NULL; // 二重指针

    a = &index;
    *a = 2;
    printf("%d\n", index);
    b = &a;
    **b = 3;
    printf("%d\n", index);
}

• 数组指针

#include <stdio.h>

int main_demo(void)
{
    int a[3] = {1, 2, 3};
    int (*p)[3] = NULL;// 表示指针指向一个包含3个元素的int数组
    p = &a;
    printf("%d\n", (*p)[2]);
    return 0;
}

int main(void)
{
    char str[3][10] = {"hello", "my", "language"};
    char* ch = NULL;
    char (*cr)[10] = NULL;

    cr = &str[0];
    printf("%s\n", *(cr+1));

    ch = str[0];
    printf("%s\n", (ch+20));
}

• 函数指针

#include <stdio.h>

int add(int a, int b)
{
    return a + b;
}

int main(void)
{
    int a = 3, b = 4;
    int (*p)(int, int) = NULL;
    p = add;
    printf("%d\n", p(a, b));
}

#include <stdio.h>

void printStr(char **ch, int len)
{
    for(int i=0; i<len; i++) {
        printf("%s\n", *(ch+i));
    }
}

void printDefined(void fn(char**, int), char **arr, int len)
{
    fn(arr, len);
}

int main(void)
{
    char* arr[3] = {"hello", "my", "c"};
    void (*p)(char**, int) = NULL;
    p = printStr;
    //printStr(arr, 3);
    //p(arr, 3);
    printDefined(p, arr, 3);
}

• 指针实现冒泡排序

#include <stdio.h>
#include <time.h>

void initArr(int* arr, int len);

void showArr(int* arr, int len);

void swap(void* left, void* right);

int cmp(void* left, void* right);

void bubbleSort(void* arr, int len, int (*cmp)(void*, void*), void swap(void*, void*))
{
    int i,j;
    for(i =0; i< len; i++) {
        for(j=0; j< len-i-1; j++) {
            if(cmp( (void *)((int*)arr + j), (void*)((int*)arr + j + 1) ) > 0) {
                swap( (void*)((int*)arr + j), (void*)((int*)arr + j + 1));
            }
        }
    }
}

int main(void)
{
    int a[10];
    initArr(a, 10);
    showArr(a, 10);
    bubbleSort(a, 10, cmp, swap);
    printf("bubbleSort : \n");
    showArr(a, 10);
}


int cmp(void* left, void* right)
{
    int x = *((int*)left);
    int y = *((int*)right);
    return x > y;
}

void swap(void* left, void* right)
{
    int tmp;
    tmp = *((int*)left);
    *((int*)left) = *((int*)right);
    *((int*)right) = tmp;
}

void initArr(int* arr, int len)
{
    srand(time(NULL));
    while(len > 0) {
        len--;
        *(arr + len) = rand() % 100;
    }
}

void showArr(int* arr, int len)
{
    int index = 0;
    while(index < len)
    {
        printf("%d\n", *(arr+index));
        index++;
    }
}