奇數的逆序寫法----偶數這個有bug，這裡主要是熟練指標的用法，針對偶數，等後續學習中再做補充 

#include <stdio.h>
#include <stdlib.h>
#define N 5
int main()
{
    int i,temp;
    int nums[N]={22,77,44,55,88};
    int *ptr_num_start = nums;
    int *ptr_num_end = nums+N-1;
    while(ptr_num_start != ptr_num_end){
       temp = *ptr_num_start;
       *ptr_num_start = *ptr_num_end;
       *ptr_num_end = temp;
       ptr_num_start++;
       ptr_num_end--;
    }
    for(i=0;i<N;i++){
        printf("%d\t",*(nums+i));
    }

    return 0;
}
 

指標訪問二維陣列的三種方法

#include <stdio.h>
#include <stdlib.h>
#define N 5
int main()
{
     int i,j;
     int nums[5][3]={
     {33,44,55},
     {23,54,75},
     {11,26,90},
     {65,68,89},
     {24,49,81}
     };
     int (*ptr_nums)[3]=nums;
     for(i=0;i<5;i++){
        for(j=0;j<3;j++){
          //  printf("%d\t",nums[i][j]);
           //printf("%d\t",*(nums[i]+j));
           // printf("%d\t",*(*(nums+i)+j));
            printf("%d\t",*(*(ptr_nums+i)+j));
        }
        printf("\n");
     }

    return 0;
}