isPowerOf2.cpp

This function will check whether a number is Power of 2 in O(1) time

Author: supriyanta

BitManipulation/isPowerOf2.cpp

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+#include<iostream>
+
+using namespace std;
+
+bool isPowerOf2(int no)
+{
+	if(no && (no & (no-1))==0)       // lets the no is x.If x is power of 2,then x & (x-1) must be equal to zero
+	return true;
+	else                             // If x isn't power of 2,then x & (x-1) will be greater than or equal to x
+	return false;
+}
+
+int main()
+{
+	int no; cin>>no;
+	
+	if(isPowerOf2(no))
+	cout<<"Yes\n";
+	else
+	cout<<"No\n";
+	
+	return 0;
+}