用指针写一个逆序显示字符串的程序,并在主函数中调用

#include "stdio.h"
#include "iostream"
using namespace std;
#define MAX 100
char result[MAX]={'\0'};
void ConverString(char* ptrstr,int counter);
void main(void)
{
char strings[MAX]={'\0'};
char* ptrStr=NULL;
char* resultStr=NULL;
int count=0;
cout<<"输入字符串"<<endl;
cin>>strings;
size_t length=sizeof(strings);
ptrStr=strings;
while(*ptrStr!='\0')
{
count++;
ptrStr++;
}
ConverString(ptrStr,count);
cout<<"逆转后输出结果为：";
for (int a=0;a<count;a++)
{
cout<<result[a];
}
cout<<endl;
}

void ConverString(char* ptrstr,int counter)
{
int a=0;
for (a=0;a<counter;a++)
{
ptrstr--;
result[a]=*ptrstr;
}
result[a+1]='\0';
}