check if subtree

/*
Given two binary trees with head reference as T and S having at most N nodes. The task is to check if S is present as subtree in T.
A subtree of a tree T1 is a tree T2 consisting of a node in T1 and all of its descendants in T1.

Example:

S:          10
              /   \
            4     6
                 /
             30

T:                  26
                      /   \
                    10   3
                   /   \     \

               4       6     3
                       /
                    30

In above example S is subtree of T.

Please note that subtree has to be having same leaves non leaves.

   10
  /
20

For example, above tree is not subtree of

         10
       /     \
    20     50
   /   \
30   40

But a subtree of

         30
       /     \
    10     50
   /  
20  

Input Format:
First line of input contains number of testcases T. For each testcase, there will be 4 lines, first of which containing the number of
edges (between two nodes) in the S tree. Next line contains N pairs (considering a and b) with a 'L' (means node b on left of a) or 'R'
(means node b on right of a) after a and b. The next two lines of every test case contain details of tree T

Output Format:
For each testcase, there will be a single line containing 0 or 1, depending on the input.

Your Task:
Complete the function isSubtree() that takes two nodes as parameter and returns true or false.

Constraints:
1 <= T <= 30
1 <= N <= 103

Example:
Input:
3
1
3 4 L
3
1 2 L 1 3 R 3 4 L
5
26 10 L 10 20 L 10 30 R 20 40 L 20 60 R
5
26 10 L 10 20 L 10 30 R 20 40 L 20 60 R
3
10 4 L 10 6 R 4 30 R
6
26 10 L 26 3 R 10 4 L 10 6 R 6 25 R 3 3 R

Output:
1
1
0

Explanation:
Testcase 3:
Structure of tree:
10 4 L 10 6 R 4 30 R
10 is root node of tree. Left child of 10 is 4 and right child of 10 is 6. Right child of 4 is 30.
*/

void fillInorder(Node* root, char arr[], int& i) 
{ 
    if (root == NULL) { 
        arr[i++] = '$'; 
        return; 
    } 
    fillInorder(root->left, arr, i); 
    arr[i++] = root->data; 
    fillInorder(root->right, arr, i); 
} 
  

void fillPreOrder(Node* root, char arr[], int& i) 
{ 
    if (root == NULL) { 
        arr[i++] = '$'; 
        return; 
    } 
    arr[i++] = root->data; 
    fillPreOrder(root->left, arr, i); 
    fillPreOrder(root->right, arr, i); 
} 









bool isSubtree(Node* t, Node* s) {
   if(s==NULL) return true;
   if(t==NULL) return false;
   
   int m=0,n=0;
   char inT[MAX] , inS[MAX];
   fillInorder(t,inT,m);
   fillInorder(s,inS,n);
   inT[m]='\0'; inS[n]='\0';
   
   if(strstr(inT, inS) == NULL) return false;
   
   m=0,n=0;
   char preT[MAX] , preS[MAX];
   fillPreOrder(t,preT,m);
   fillPreOrder(s,preS,n);
   preT[m]='\0'; preS[n]='\0';
   
   return (strstr(preT, preS) != NULL);
   
}