习题2.25应该还要补充变量的值

顺便调整了一下格式
```cpp
 #include <iostream>
 using namespace std;

 int main()
 {
    int i, *ip = 0;
    int *ip1, ip2;
    cout << "i=" << i << endl;
    cout << "ip2=" << ip2 << endl;
    return 0;
 }
```

the output on my laptop :
```d
i=134514651
ip2=-1218498560
```