Infix To postfix Evaluation using stack and array - data-structures

Question

i am trying to convert infix to postfix but unable to get any output although program is free of error and logically correct. its just showing the value of m. I tried to print hello inside loop , but its unable to print that.I can't understand why its not going inside loop. Can't figure out the exact reason behind it.
#include <bits/stdc++.h>
#define m 21
using namespace std;
int isitoperattor(char c) //to find precdenec of operator
{
if(c=='+'||c=='-')
return 1;
if(c=='*' || c=='/')
return 2;
if(c=='('||c==')')
return 3;
}
void infixtopostfix(char str[m]){
char out[m];
cout<<m<<endl;
stack <char> s;
static int k;
for(int i=0;i<m;i++)
{
cout<<"hello";
if((str[i]>='a' && str[i]<='z') || (str[i]>='A' && str[i]<='Z')){
out[k]=str[i];
k++;}
else if (str[i]=='(')
s.push(str[i]);
else if (str[i]==')'){
//int j=i-1;
while(s.top()!='('){
out[k]=s.top();
s.pop();
k++;
//-;
}
s.pop();
}
else
{
if(isitoperattor(str[i]) && (isitoperattor(str[i])<isitoperattor(s.top()))){
while(isitoperattor(s.top())>=isitoperattor(str[i])){
out[k]=s.top();
s.pop();
k++;
}
}
}
s.push(str[i]);
}
}
while(!s.empty())
{
out[k]=s.top();
s.pop();
k++;
}
//string out;
for(int j=0;j<k;j++)
cout<<out[j];
}
int main()
{
char str[m]="a+b*(c^d-e)^(f+g*h)-i";
infixtopostfix(str);
return 0;
}