Copy and reverse char* in the C++ - c++

Question

I would like to copy reversed char* to the another char*. I miss one letter in the second line of the output.
I did:
#include <iostream>
using namespace std;
void cp(char *str2, char *str1){
char *pom1 = str1;
while(*pom1){
pom1++;
}
char* pom2 = str2;
while(*pom1 != *str1){
pom1--;
*pom2 = *pom1;
pom2++;
}
*pom2 = '\0';
}
int main()
{
char *str1 = "ppC", str2[10] = "Witaj";
cout << "Napis str2 "<< str2 << endl;
cp(str2,str1);
cout << "Napis str2 "<< str2 << endl;
cp(str2,"CJP");
cout << "Napis str2 "<< str2 << endl;
return 0;
}
and the output is:
Napis str2 Witaj
Napis str2 Cp
Napis str2 PJC
While it should be:
Napis str2 Witaj
Napis str2 Cpp
Napis str2 PJC

Answer 1

The bug is in this statement of the function
while(*pom1 != *str1){
There must be
while( pom1 != str1){
Take into account that string literals have type of constant arrays. So for example variable str1 has to be declared as
const char *str1 = "ppC";
Also the function should be declared as
void cp( char *str2, const char *str1 );
Also It will be useful to know that there is standard algorithm std::reverse_copy declared in header <algorithm>:)

Answer 2

There's reverse_copy in the stdlib
... and that it's used like:
template <typename CharT, size_t Ndest>
void cp(CharT (&dest)[Ndest], CharT const *src){
auto f = src, l = src + std::strlen(src);
assert(std::distance(f,l) < Ndest);
*(std::reverse_copy(f, l, dest)) = '\0';
}
So, see it Live On Coliru
#include <iostream>
#include <algorithm>
#include <cstring>
#include <cassert>
template <typename CharT, size_t Ndest>
void cp(CharT (&dest)[Ndest], CharT const *src){
auto f = src, l = src + std::strlen(src);
assert(std::distance(f,l) < Ndest);
*(std::reverse_copy(f, l, dest)) = '\0';
}
#include <iostream>
int main()
{
char str1[] = "ppC";
char str2[10] = "Witaj";
std::cout << "Napis str2 "<< str2 << std::endl;
cp(str2, str1);
std::cout << "Napis str2 "<< str2 << std::endl;
cp(str2,"CJP");
std::cout << "Napis str2 "<< str2 << std::endl;
return 0;
}

Answer 3

Just use the Standard Library, std::reverse_copy() in this case:
std::reverse_copy( input , input + strlen( input ) , output );

Answer 4

copy paste solution
int len(const char *p) {
int c = 0;
while (*p != '\0')
{
c++;
p++;
}
return(c);
}
void cp(char *str2, const char *str1){
if(!(len(str2)<len(str1))){
const char *pom1 = str1;
while(*pom1){
pom1++;
}
char* pom2 = str2;
while( pom1 != str1){
pom1--;
*pom2 = *pom1;
pom2++;
}
*pom2 = '\0';
}
}