Given an array of **N** element. The task is to check if it is Inorder traversal of any Binary Search Tree or not. Print “Yes” if it is Inorder traversal of any Binary Search Tree else print “No”.

Examples:

Input : arr[] = { 19, 23, 25, 30, 45 } Output : Yes Input : arr[] = { 19, 23, 30, 25, 45 } Output : No

The idea is to use the fact that the inorder traversal of Binary Search Tree is sorted. So, just check if given array is sorted or not.

// C++ program to check if a given array is sorted // or not. #include<bits/stdc++.h> using namespace std; // Function that returns true if array is Inorder // traversal of any Binary Search Tree or not. bool isInorder(int arr[], int n) { // Array has one or no element if (n == 0 || n == 1) return true; for (int i = 1; i < n; i++) // Unsorted pair found if (arr[i-1] > arr[i]) return false; // No unsorted pair found return true; } // Driver code int main() { int arr[] = { 19, 23, 25, 30, 45 }; int n = sizeof(arr)/sizeof(arr[0]); if (isInorder(arr, n)) cout << "Yesn"; else cout << "Non"; return 0; }

Output:

Yes

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