#include <bits/stdc++.h>
using namespace std;
int getValidStrings(vector<int> &arr){
	int n=arr.size();
	int ans=1; //assume to have atleast one possible ans
	for(int i=0;i<=n-2;i++){
		int diff=abs(arr[i]-arr[i+1]);
		if(arr[i]==arr[i+1]){   //observation 1     
			ans=ans*2;
		}
		else if(diff>1){
			return 0;
		}
		else {                //obervation 2
			ans=ans*1;
		}
	}
	return ans;
 
}
int main() {
	// your code goes here
	vector<int>arr={1,2,3,2,1};
	cout<<"The count of valid strings that satisfy the conitions are:"<<getValidStrings(arr);
	return 0;
}

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