Check String Chaining

/***
You are given an array of Strings, return TRUE if and only if All the strings can be connected in one chain.
Condition for connectivity is , if the last character of one string matches first character of second string, the two string can be connected.
Example : String []arr ={"abc", "cde", "cad" , "def" , "eac"} will return TRUE coz all strings can be connected in one chain
"abc"->"cde"->"eac"->"cad"->"def"
Another Example : String []arr ={"acb" , "cde", "def", "ead" } returns False coz "cde"->"ead"->"def" is the possible chain but “acb” is left out.
Note : Its not necessary to start with the first String and form the chain, It may happen that you won’t get a chain if you start with first string but you can get a
chain if you Start with any other String. If there exists a possible chain, then your solution should return True.
In the second example , if the first String was suppose “fcb” , then a possible chain would have exists "cde"->"ead"->"def"->"fcb" so True.
***/

/**
Idea: only to check the first item and last item in string
case1: no connection
data structure: linked list
**/

#include<iostream>
#include<string>

using namespace std;

bool isChaining(string *str, int sz, int index, int rd, bool *b) {
       if(rd == 0) return true;
      
       for(int i = 0; i<sz; i++) {
              if(b[i] && str[index].back() == str[i].front()) {
                     b[i] = false;
                     if(isChaining(str, sz, i, rd-1, b)) return true;
                     b[i] = true;
              }
       }
       return false;
}

void main() {
       string str[] = {"cde", "cad" , "def" , "eac", "abc" };
       int sz = sizeof(str) / sizeof(string);
       bool *b = new bool[sz];
       memset(b, true, sz);
       for (int i = 0; i<sz; i++)
       {
              b[i] = false;
              if(isChaining(str, sz, i, sz-1, b))
                     cout<<"true"<<endl;
              else memset(b, true, sz);
       }

}

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