帮我解决一道C++编程题：求字符串str的长度，要求用指针访问字符串。

#include <iostream>
using namespace std;

int main()
{
char str[100];
gets(str);
char *p=str;
int cnt=0;
while(*(p+cnt))
{
cnt++;
}
printf("length=%d\n",cnt);
return 0;
}

#include <iostream> #include <string> using namespace std; void main() { string TestString = "

#include <string.h> #include <iostream> using namespace std;

void main() { string str="this is a string"; const char *p=str.c_str(); int count=0; while(*p++!=NULL) count++; cout<<count<<endl; }

#include "stdafx.h" #include <iostream> using namespace std; int Getstrlen(char *p) { int nLen = 0; while (*p) { *p++; nLen++; } return nLen;

}

int main() { char *str = "aaaaaaaaaa"; cout << "字符串长度为：" << Getstrlen(str); }