我想问一下，这个程序应该怎么改才可以得到正确的答案？弄不明白，请各位高手看一看。

#include"iostream"
#define Max 256
using namespace std;
typedef struct
{
    char ch[Max];
    int lenght;
}
SeqString;
void InitString(SeqString *s)
{
    char ch;
    int i=0;
    while((ch=getchar())!='\n'&&i<Max)
        s->ch[i++]=ch;
    s->lenght=i;
}
int Strlen(SeqString *s)
{
    return (s->lenght);
}
SeqString *substr(SeqString *s,int pos,int len,SeqString *sub)
{
    int i;
    if(pos<1||pos>s->lenght||len<1||len>s->lenght)
    {
        cout<<"error!!"<<endl;
    return NULL;
    }
    for(i=0;i<len;i++)
        sub->ch[i]=s->ch[pos+i-1];
    sub->lenght=len;
    return (sub);
}
int strcmp(SeqString *s,SeqString *t)
{
    int i,j;
    for(i=1,j=1;i<s->lenght,j<t->lenght;)
        {
            if(s->ch[i]==t->ch[j])
            {
                i++;
                j++;
            }
            else
            {
                i=i-j+2;
                j=1;
            }
        }
        if(j>t->lenght)
            return (i-t->lenght+1);   
        else
            return 0;
   
}
void main()
{
    int i,k;
    SeqString *s,*t,*r;
    cout<<"构造一个串s!!"<<endl;
    InitString(s);
    cout<<"构造一个串t!!"<<endl;
    InitString(t);
    cout<<"请输入子串在主串中位置:";
    cin>>i;
    k=strcmp(substr(s,i,Strlen(t),r),t);
    cout<<k;
}
编译时出现这样的警告：
C:\VC++6.0简体中文版 编程工具\cv++6.0\MSDev98\MyProjects\program46\2011.4.29.cpp(62) : warning C4700: local variable 's' used without having been initialized
C:\VC++6.0简体中文版 编程工具\cv++6.0\MSDev98\MyProjects\program46\2011.4.29.cpp(64) : warning C4700: local variable 't' used without having been initialized
C:\VC++6.0简体中文版 编程工具\cv++6.0\MSDev98\MyProjects\program46\2011.4.29.cpp(67) : warning C4700: local variable 'r' used without having been initialized

2011.4.29.obj - 0 error(s), 3 warning(s)
帮忙看一下，谢谢啦。