字符连接函数改错c++

#include <iostream.h>
char mystrcat(char a[],char b[])
{
int i=0,j=0,k,l;
while(a[i])
{
i++;
k=i;
}
while(b[j])
{
j++;
l=j;
}
for(i=k,j=0;i<k+l;i++,j++)
{
a[i]=b[j];
}
return a[i];
}
void main()
{
char a[100],b[100];
cout<<"请输入数组"<<endl;
cin>>a;
cout<<"请输入数组"<<endl;
cin>>b;
cout<<"数组为:"<<mystrcat(a,b)<<endl;
}

没有错误但是改正不了，请各位兄弟姐妹帮我指出并改正，谢谢！！！

char* mystrcat(char a[],char b[])
{
int i=0,j=0,k,l;
while(a[i])
{
i ++;
k = i;
}
while(b[j])
{
j ++;
l = j;
}
for(i = k, j = 0; i < k + l; i ++, j ++)
{
a[i] = b[j];
}
return a;
}

int main()
{
char a[100],b[100];
cout<<"请输入数组"<<endl;
cin>>a;
cout<<"请输入数组"<<endl;
cin>>b;
cout<<"数组为:"<<mystrcat(a,b)<<endl;

return 0;
}

#include <iostream.h>
char *mystrcat(char a[],char b[])
{
int i=0,j=0,k,l;
while(a[i])
{
i++;
k=i;
}
while(b[j])
{
j++;