String permutations

#1

I am not able to understand why some of the test cases are going wrong in my following code
#include
#include
#include <math.h>
#include <stdlib.h>

using namespace std;
void recper(string str, string osf)
{ if (str.size()==0)
{ cout<<osf<<endl;
return; }

	bool arr[26]={0};
for(int i=0; i<str.size(); i++)

{
char ch=str[i];
if(arr[ch-‘A’]==false)
{
arr[ch-‘A’]=true;
string ros = str.substr(0,i)+str.substr(i+1,str.size());
recper(ros,osf+ch);
} }
}

int main()
{
string str;
cin>>str;

recper(str,"");


return 0;

}

#2

@sghosh2018
You code prints incorrect output for input like BAA.
The output is not lexicographically sorted.
You need to use sorting somewhere.