Problem using Schmidt - Samoa Encryption

void keygen(long &publickey,long &privatekey,long &p,long &q)
{
     p = genrndprimes(0,10);
     q = genrndprimes(10,30);
    long n = power(p,2)*q;
    long d = (1/n)%lcm((p-1),(q-1));

    publickey = n;
    privatekey = d;

}

void encrypt(char *str,long *nums,long key)
{
    for(long i=0;i<strlen(str);i++)
    {
        nums[i]=(long)power(str[i],key)%key;
    }
}

void decrypt(char *str,long *nums,long key,long p,long q)
{
        for(long i=0;i<strlen(str);i++)
    {
        str[i]=(long)power(nums[i],key)%(p*q);
    }

}

void main()
{
	char m[]="Hello!!";
	long *j = new long[strlen(m)];
	long p,q,privtkey,publkey;
	keygen(publkey,privtkey,p,q);
	encrypt(m,j,publkey);
	puts(m);
	cout<<"\n\n";
	decrypt(m,j,privtkey,p,q);
	cout<<"\n\n";
	puts(m);
	getch();
	
}