将一个数组的数据按相反的顺序储存;int a[10]={1,2,3,4,5,6,7,8,9,0},处理完成后,数组的内容变成{0,9,8,7,6,5,4,3,2,1}
思路:
1.利用数组,将数组的首地址和末地址分别保存为left,right.首末位置的元素两两相互交换,left向右移,left++。right向左移,right–。当left等于right时,跳出循环。
具体代码:
#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
void Reserve(int arr[], int sz)
{
int left = 0;
int right = sz - 1;
while (left < right)
{
int temp = arr[left];
arr[left] = arr[right];
arr[right] = temp;
left++;
right--;
}
}
int main()
{
int arr[10] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 0 };
int sz = sizeof(arr) / sizeof(arr[0]);
Reserve(arr, sz);
int i = 0;
for (i = 0; i < 10; i++)
{
printf("%d ", arr[i]);
}
getchar();
return 0;
}
结果:
2.利用指针:利用指针来实现left,right
具体代码:
#include<stdio.h>
#include<assert.h>
void Reserve(int *left,int *right)
{
assert(left != NULL);
assert(right != NULL);
while (left < right)
{
int temp = *left;
*left = *right;
*right = temp;
left++;
right--;
}
}
int main()
{
int arr[10] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 0 };
int sz = sizeof(arr) / sizeof(arr[0]);
Reserve(arr ,arr+sz-1);
int i = 0;
for (i = 0; i < 10; i++)
{
printf("%d ",arr[i]);
}
getchar();
return 0;
}
结果: